CBSE Class 10 All Subjects Revision Worksheet Set 07

SUBJECT - SOCIAL SCIENCE

Question Q.1) Read newspapers daily, collect 5-6 news related to politics. Paste these pictures and write reports on the same.
Answer: To successfully complete this project, select 5 - 6 major national or local political developments from daily newspapers like The Times of India or The Hindu. Clip the relevant images/articles, paste them onto your A-4 sheets, and use the structural template below to draft your reports.

Sample Political Report Template:

• Heading of the News: E.g., Announcement of New Educational Policy Reforms.
• Date of Publication & Source: E.g., June 14, 2026 - The Hindu.
• Key Figures Involved: Prime Minister, Union Minister of Education, and State Representatives.
• Core Summary: State what the development is about, who is directly impacted, and why it is in the limelight.
• My Personal Perspective: Summarize your thoughts on the social and economic impact of this policy.

Suggested News Topics for Your Collection:

1. Policy Reforms: Government decisions on healthcare, tax modifications, or educational policies.
2. Bilateral Meetings: Visits by foreign heads of state and new trade partnerships.
3. Parliamentary Debates: Passing of major bills or assembly sessions.
4. Elections/Campaigns: Local state assembly updates, manifesto highlights, or democratic rallies.
5. Public Infrastructural Initiatives: Launch of national highway expansions or green transit systems.

In simple words: Get a daily newspaper, cut out 5 or 6 political articles with pictures, paste them, and write a summary explaining what the news is about and how it affects the public.

Exam Tip: Underline the key nouns and administrative terms (such as 'legislation', 'bilateral', or 'resolution') in your reports to grab the evaluator's attention.

Question Q.2) Collect 2-3 electricity bills of your house and find the average consumption of a month. Describe the ways to minimize your monthly consumption of electricity.
Answer:

Part A: Average Consumption Calculation

Gather three consecutive electricity bills (e.g., April, May, and June). Below is a sample calculation showing how to find the average:

• Bill 1 (April): 280 Units (kWh)
• Bill 2 (May): 340 Units (kWh)
• Bill 3 (June): 310 Units (kWh)

Calculation for Average Monthly Consumption: \[ \text{Average Monthly Consumption} = \frac{\text{Total Units Consumption}}{\text{Number of Months}} \] \[ \text{Average Monthly Consumption} = \frac{280 + 340 + 310}{3} = \frac{930}{3} = 310 \text{ Units} \]

Part B: Measures to Minimize Monthly Electricity Consumption

To reduce electricity consumption at home, the following practices are recommended:

1. Switch to LED Lighting: Replace traditional incandescent bulbs with energy-efficient LED bulbs. LEDs use up to 75% less energy and last significantly longer.
2. Use Star-Rated Appliances: Install home appliances (ACs, refrigerators, geysers) with 5-star Bureau of Energy Efficiency (BEE) ratings to ensure low energy consumption.
3. Adopt Smart Power Practices: Avoid keeping electronics on standby mode. Turn off appliances at the main switchboards when not in use to cut down on idle power draw.
4. Optimize Air Conditioning: Set your air conditioner to a comfortable 24 degrees Celsius instead of lower temperatures. Every degree higher saves nearly 6% of the running electricity.
5. Maximize Natural Daylight: Keep curtains open during the daytime to utilize natural sunlight instead of relying on artificial indoor lighting.

In simple words: Write down the power units used in 3 of your bills and find the average. Then, list easy ways to save electricity, like turning off unused lights, using LED bulbs, and keeping the AC at 24 degrees.

Exam Tip: Present your monthly power units in a clean tabular format before performing the mathematical average calculation to make it visually clear.

Question Q.3) Make a project on any one of the following topics:- First aid guide for fracture, First aid guide for poisoning, First aid guide for cuts and bruises, First aid guide for heat and cold waves.
Answer:

First Aid Guide for Fractures (Project Report Outline)

1. Understanding Fractures: A fracture is a medical term used to describe a broken bone. It can happen due to high-impact falls, vehicular accidents, or sports injuries. Fractures are broadly classified into two categories:

• Closed (Simple) Fracture: The bone breaks but the skin remains intact.
• Open (Compound) Fracture: The broken bone pierces through the skin, presenting a risk of infection.

2. Symptoms of a Fracture:

• Severe pain and tenderness at the site of the injury.
• Swelling, bruising, and visible deformity.
• Inability to move the affected body part.
• A grating sensation (crepitus) or snapping sound during the injury.

3. Step-by-Step First Aid Protocol:

1. Stop the Bleeding: If there is an open wound, apply gentle pressure with a sterile bandage to control blood loss. Avoid touching the bone.
2. Immobilize the Injured Area: Do not attempt to realign the bone. Use a splint (such as a wooden plank, ruler, or folded cardboard) secured with bandages to keep the limb completely still.
3. Apply Cold Packs: Wrap ice in a clean cloth and apply it to the injured area to reduce swelling and relieve pain. Avoid applying ice directly to the skin.
4. Treat for Shock: If the patient feels faint, have them lie flat with their feet slightly elevated. Cover them with a light blanket.
5. Seek Emergency Medical Help: Call an ambulance immediately or transport the injured person safely to the nearest hospital.

4. What NOT to Do:

• Do not massage the affected area.
• Do not move the patient if you suspect a spine or neck injury.
• Do not allow the patient to eat or drink anything in case they require surgery.

In simple words: This project guide explains that a fracture is a broken bone. First aid steps include stopping any bleeding, keeping the broken area still with a splint, applying ice to reduce swelling, and calling a doctor immediately.

Exam Tip: Include a diagram of a simple splint and sling on your project sheet to enhance the visual appeal of your guide.

Question Q.4) Prepare a role play on any one of the following topics:- Pesticides in aerated drink, Dumping wastes into a nearby river, Hoarding by traders, Recycling of waste.
Answer:

Role Play Script: Dumping Wastes into a Nearby River

Characters:

• Ramesh: A concerned local farmer who relies on the river for irrigation.
• Mr. Khanna: An industrial supervisor at a nearby chemical factory.
• Dr. Ananya: An environmental scientist and activist.

[Scene: A riverbank near a village. Ramesh is standing near the water, looking upset. Mr. Khanna stands nearby holding clipboard files.]

Ramesh: (With distress) Mr. Khanna, look at this water! It has turned dark grey, and a thick chemical foam is floating on it. Our crops are dying, and the cattle are falling sick after drinking from the river. How can your factory dump untreated toxic waste directly into our lifeline?

Mr. Khanna: (Defensively) Ramesh, you need to understand that our factory provides jobs to hundreds of villagers. Treating this industrial waste on-site requires expensive machinery that we cannot afford. We are keeping our business running, which helps your village economy.

Dr. Ananya: (Stepping in with research papers) That is a short-sighted argument, Mr. Khanna. Economic progress cannot come at the cost of public health. This river supplies drinking water to three downstream districts. My lab tests show that the water contains heavy metals like lead and cadmium, which are highly carcinogenic.

Mr. Khanna: (Skeptically) But what else can we do? We cannot simply shut down our production line.

Dr. Ananya: You don't have to shut down. The factory must install an Effluent Treatment Plant (ETP). The water can be purified and recycled within your plant. Additionally, the government offers subsidies to clean industries. We will report this dumping to the Pollution Control Board if you do not implement corrective measures immediately.

Ramesh: Yes, Mr. Khanna! A clean river is our fundamental right. We want our livelihoods protected, not poisoned.

Mr. Khanna: (Realizing the gravity of the situation) I see your point. I will discuss the installation of an ETP with our management team this week. Healthy villagers are, after all, our best workforce.

[Scene Ends with Ramesh and Dr. Ananya shaking hands as Mr. Khanna steps back to inspect the drain outlet.]
In simple words: This script is a 3-person play where a farmer and a scientist confront a factory manager for polluting their river. They convince him to install a water treatment system to protect the community.

Exam Tip: Structure your script with clear character names in bold, and write the stage directions in parentheses to show a proper theatrical format.

Question Q.5) Watch discovery channel and collect information about endemic and endangered species. Write a report on the same.
Answer:

Report: Endemic and Endangered Species of India

1. Introduction: Biodiversity refers to the vast variety of flora and fauna on Earth. Two critical groups of species require targeted conservation focus:

• Endemic Species: Plants or animals found exclusively in a specific geographic area and nowhere else in the world (e.g., Nilgiri Tahr in the Western Ghats).
• Endangered Species: Organisms at a high risk of extinction due to rapid population decline, habitat loss, or poaching (e.g., Bengal Tiger).

2. Endemic Species of India:

• Lion-Tailed Macaque (Macaca silenus): This arboreal Old World monkey is endemic to the rainforests of the Western Ghats in South India. It is easily recognized by its silver-white mane. Habitat fragmentation caused by tea and coffee plantations has severely reduced its population.
• Sangai / Brow-Antlered Deer (Rucervus eldii): Endemic to Manipur, this deer lives on the floating biomass (phumdis) of Loktak Lake. It is adapted to walk on floating marshy land.

3. Endangered Species of India:

• Bengal Tiger (Panthera tigris tigris): India is home to the largest population of wild tigers. However, habitat encroachment, human-wildlife conflict, and poaching for their skin and bones have placed them on the endangered list. Conservation initiatives like 'Project Tiger' help protect their numbers.
• Indian Rhinoceros (Rhinoceros unicornis): Found primarily in Assam's Kaziranga National Park, these animals face serious threats from poaching for their horns, as well as seasonal floods that destroy their grassland habitat.

4. Conclusion: Protecting these species is crucial for maintaining ecological balance. When a species goes extinct, it disrupts the entire food chain. Strong environmental laws, habitat protection, and anti-poaching measures are essential to preserve India's natural heritage.
In simple words: Endemic species live only in one specific region (like the Lion-Tailed Macaque in South India). Endangered species (like the Tiger) are at risk of disappearing forever. Protecting them helps keep our ecosystems healthy and balanced.

Exam Tip: Clearly define the difference between 'endemic' and 'endangered' at the beginning of your report to set a strong academic tone.

Question Q.6) Mark all the wild life sanctuaries, bird sanctuaries and national park in the physical map of India.
Answer: To complete this activity, obtain a physical outline map of India and mark the key protected areas listed below:

1. Key National Parks to Mark:

• Jim Corbett National Park: Locate in Uttarakhand (North India) - famous for tigers.
• Kaziranga National Park: Locate in Assam (Northeast India) - home to the one-horned rhinoceros.
• Gir National Park: Locate in Gujarat (West India) - the exclusive home of Asiatic Lions.
• Kanha National Park: Locate in Madhya Pradesh (Central India) - renowned for its swamp deer.

2. Key Wildlife Sanctuaries to Mark:

• Periyar Wildlife Sanctuary: Locate in Kerala (South India) - famous for elephants and tigers.
• Ranthambore Wildlife Sanctuary: Locate in Rajasthan (West-Central India).
• Mudumalai Wildlife Sanctuary: Locate at the tri-junction of Tamil Nadu, Karnataka, and Kerala.

3. Key Bird Sanctuaries to Mark:

• Bharatpur Bird Sanctuary (Keoladeo Ghana National Park): Locate in Rajasthan - a winter nesting ground for migratory birds.
• Sultanpur Bird Sanctuary: Locate in Haryana (near Delhi).
• Salim Ali Bird Sanctuary: Locate in Goa (West Coast).

In simple words: Get a physical map of India and use a pen to mark these places: Jim Corbett in Uttarakhand, Kaziranga in Assam, Gir in Gujarat, and Bharatpur in Rajasthan.

Exam Tip: Use different symbols or color codes (e.g., green triangles for National Parks, red dots for Bird Sanctuaries) and include a neat key/legend on the map.

SUBJECT - INFORMATION TECHNOLOGY

Question 1. Prepare a PPT using Open Office Organization Impress on the topic "Information Technology".
Answer: Below is a detailed slide-by-slide structure and content guide to help you build your presentation using OpenOffice Impress:

• Slide 1: Title Slide
  • Title: The Impact and Future of Information Technology
  • Subtitle: Empowering the Digital Era
  • Details: Presented by [Your Name], Class X
• Slide 2: Introduction to IT
  • Content: Define Information Technology as the use of computer systems, storage, networking, and physical devices to manage, process, and secure digital data.
  • Visual Idea: Add a flow diagram showing Data Input -> Processing -> Output.
• Slide 3: Core Pillars of IT
  • Hardware (servers, processors, smart devices)
  • Software (operating systems, database software, web apps)
  • Telecommunications (fiber optics, 5G wireless networks, internet protocols)
• Slide 4: Databases and Data Management
  • Content: Explain how databases store large amounts of structured data. Introduce Relational Database Management Systems (RDBMS) like OpenOffice Base, which use tables, queries, and SQL.
• Slide 5: IT in Daily Life
  • E-Commerce (online shopping platforms)
  • E-Education (smart classrooms, online courses)
  • Digital Banking (cashless transactions)
• Slide 6: Emerging Trends in IT
  • Artificial Intelligence & Machine Learning
  • Cloud Computing (storing data on remote servers)
  • Cybersecurity (protecting digital networks from unauthorized access)
• Slide 7: Conclusion
  • IT has transformed from a support tool into a vital driver of global development and economic growth.
• Slide 8: Bibliography & Thank You
  • List references and include a "Thank You" note.

In simple words: This guide outlines how to build an 8-slide presentation about IT. It covers basic concepts, databases, daily uses, future trends (like AI), and concludes with a thank-you slide.

Exam Tip: Avoid overcrowding slides with long paragraphs. Use clear bullet points and simple background layouts to keep your presentation looking professional.

Question 2. Prepare a database of students using OO Base calc-1 .(minimum 50 records)
Note: Bring the above mentioned work in C.D.
Whatsoever has been covered should be revised.
Answer: To complete this database project in OpenOffice, use Calc as a spreadsheet table or import it directly into OpenOffice Base.

Step-by-Step Implementation in OpenOffice Calc:

1. Open a new spreadsheet in OpenOffice Calc.
2. Create the following column headers in Row 1: Roll_No, First_Name, Last_Name, Class, Section, DOB, Contact_No, City.
3. Enter 50 distinct student records, ensuring proper formatting (e.g., date formatted as YYYY-MM-DD).
4. Save the file with a clear name (e.g., Student_Database_ClassX.ods) and burn it to a CD as instructed.

Sample Layout of the Database:

In simple words: Create a table in OpenOffice Calc with 50 student records, using columns like Roll Number, Name, Class, Date of Birth, and City. Save the file and copy it to a CD.

Exam Tip: Ensure that the field types are correct (e.g., numeric format for Roll_No and date format for DOB) to avoid formatting errors when importing the file into OO Base.

SUBJECT - ENGLISH

Question (a) Write the book review of "The Prince and the Pauper" in your own words in about 250-300 words.
Answer: Mark Twain's classic novel, The Prince and the Pauper, is a brilliant critique of class divisions in Tudor England. Set in the mid-sixteenth century, the story follows two identical boys born on the very same day: Prince Edward Tudor, the heir to the British throne, and Tom Canty, a poor boy raised in London's slums. A chance meeting at Westminster Palace leads them to swap clothes out of curiosity, which sets off a series of unexpected events when they are mistaken for each other. Through this swap, Mark Twain explores the stark contrast between royalty and poverty. As Tom struggles to adapt to the complex rules of the royal court, Edward is cast out into the harsh streets of London. This experience gives the young prince a firsthand look at the suffering of his poorest subjects, helping him grow into a compassionate and fair ruler. The novel is beautifully written, blending historical fiction, humor, and social commentary. It highlights the basic truth that human worth is not determined by birth or clothing. Twain's storytelling keeps readers engaged while delivering a timeless message about empathy and justice. The Prince and the Pauper is an outstanding read that remains highly relevant today, urging us to look past appearances and understand the lives of others.
In simple words: This book review explains how a poor boy and a prince swap places. It shows that true character and empathy matter far more than social class or expensive clothing.

Exam Tip: A great book review should include the author's name, the setting of the story, key themes, and a brief summary of the plot without giving away the ending.

Question (b) Compare and contrast any two characters from this book.
Answer:

Character Comparison: Prince Edward Tudor vs. Tom Canty

Prince Edward and Tom Canty serve as the two main characters in the novel. While they look nearly identical, their upbringings and perspectives on life are poles apart:

• Similarities:
  • Physical Appearance: Both boys look identical, which allows them to easily swap places without anyone suspecting the switch.
  • Age and Intellect: Both are intelligent, quick learners, and possess a strong sense of justice and fairness.
• Differences:
  • Social Upbringing: Prince Edward is raised in luxury, surrounded by servants and formal rules at the royal court. Tom Canty, on the other hand, grows up in the poverty of Offal Court, dealing with hunger and abuse from his father.
  • Ambitions: Before the swap, Tom dreams of the wealth and easy life of a prince. Edward, tired of strict court protocols, wishes for the freedom to run, play in the mud, and explore the streets without restrictions.
  • Behavior in the Swapped Roles: While Tom struggles to adapt to the royal court and finds its rules suffocating, Edward is shocked by the cruelty and injustice faced by the poor in London's slums.

In conclusion, their experiences in each other's shoes change both boys. Tom learns that power comes with heavy responsibilities, while Edward develops the empathy needed to become a kind and fair king.
In simple words: Prince Edward and Tom Canty look exactly alike but grow up in very different worlds. By swapping places, both boys learn valuable lessons about responsibility, poverty, and empathy.

Exam Tip: Use a Venn diagram or clear bullet points to structure your comparison, making the similarities and differences easy to read.

Question (c) Choose a scene of your choice from the novel and convert it into a play by writing the dialogues of different characters.
Answer:

Play Adaptation: The First Meeting at Westminster Palace

Characters:

• Prince Edward Tudor: The young Prince of Wales, dressed in fine royal robes.
• Tom Canty: A poor boy from Offal Court, dressed in tattered rags.
• Palace Guard: A stern, overprotective royal guard.

[Scene: The majestic gates of Westminster Palace. Tom Canty is peering through the iron bars, looking on in wonder. A Guard suddenly grabs him and throws him to the ground.]

Palace Guard: (Shouting angrily) Get back, you filthy beggar! How dare you stare at the royal family with those muddy eyes? Begone!

Tom Canty: (Trembling with fear) I mean no harm, good sir! I only wished to catch a glimpse of the real prince...

[Prince Edward overhears the shouting from the palace courtyard and steps forward.]

Prince Edward: (Authoritatively) Stop at once, guard! Release the boy. How dare you treat a subject of my father's kingdom with such cruelty? Open the gates and bring him inside.

Palace Guard: (Bowing deeply) As you command, Your Highness. (Opens the gates and pushes Tom forward gently).

[Tom enters the room, looking around in awe. He bows low before the Prince.]

Prince Edward: (Kindly) Do not be afraid, friend. You look tired and hungry. What is your name, and where do you come from?

Tom Canty: My name is Tom Canty, Your Highness. I live in Offal Court, far from this beautiful palace.

Prince Edward: Offal Court? That sounds like an interesting place. Tell me, what is your life like there? Do you get to run, play, and swim in the river with other children?

Tom Canty: Yes, Your Highness. We swim in the canals, run in the streets, and play in the mud. It is quite fun when we are not hungry.

Prince Edward: (Sighing wistfully) I would give up my royal crown just to play in the mud for a single day! Say, look at us. We are of the same height and have the same eyes. Let us swap our clothes for a moment, just to see what it feels like!

Tom Canty: (Hesitant) Oh, I do not think that is a wise idea, Your Highness...

Prince Edward: (Laughing) Come now, it is only a harmless game! Let us begin the switch.

[They step behind a screen to swap clothes, setting the story in motion.]
In simple words: This script adapts the scene where Prince Edward saves Tom from an angry guard at the palace gates. They talk about their lives and decide to swap clothes out of curiosity.

Exam Tip: Use italicized stage directions in parentheses to describe character movements and emotions, giving your script a professional touch.

GENERAL HOMEWORK (Page 2)

Question Q.1) Write a minimum of 5 recipes of summer drinks and make also them practically. Write them in the form of a booklet by making/ pasting pictures. Decorate its cover page too.
Answer: Below are the recipes for 5 classic summer drinks that you can prepare at home and compile into your project booklet:

1. Fresh Lemon Shikanji (Traditional Lemonade)

• Ingredients: 1 fresh lemon, 2 tablespoons sugar, a pinch of black salt, a pinch of roasted cumin powder, and chilled water.
• Preparation: Squeeze the lemon juice into a glass of chilled water. Add the sugar, black salt, and roasted cumin powder. Stir well until the sugar dissolves completely. Garnish with mint leaves and serve.

2. Aam Panna (Raw Mango Cooler)

• Ingredients: 2 raw green mangoes, 1/2 cup sugar/jaggery, 1 teaspoon roasted cumin powder, 1 teaspoon black salt, and a handful of fresh mint leaves.
• Preparation: Boil the raw mangoes until they soften. Once cooled, peel them and scrape out the pulp. Blend the pulp with sugar, black salt, cumin powder, and mint leaves into a smooth paste. Mix 2 tablespoons of this concentrate with chilled water and ice cubes.

3. Spiced Buttermilk (Chaach)

• Ingredients: 1 cup fresh yogurt, 2 cups cold water, 1/2 teaspoon roasted cumin powder, a pinch of black salt, and finely chopped coriander.
• Preparation: Whisk the yogurt and cold water together in a large pitcher. Add the black salt and roasted cumin powder. Garnish with fresh coriander and mint before serving.

4. Mint Jaljeera

• Ingredients: 1 tablespoon Jaljeera powder, 1 glass water, 1 teaspoon lemon juice, mint leaves, and ice.
• Preparation: Mix the Jaljeera powder and lemon juice into a glass of cold water. Stir in fresh mint leaves and serve chilled with ice cubes.

5. Watermelon Mint Cooler

• Ingredients: 2 cups deseeded watermelon chunks, 5-6 fresh mint leaves, 1 teaspoon lemon juice, and a pinch of black salt.
• Preparation: Blend the watermelon chunks and mint leaves together. Strain the juice, stir in the lemon juice and black salt, and serve over ice.

In simple words: This guide provides easy recipes for 5 classic summer drinks: Lemon Shikanji, Aam Panna, Spiced Buttermilk, Mint Jaljeera, and Watermelon Mint Cooler.

Exam Tip: Take colorful photos of your drinks, paste them into your booklet, and write a brief note describing the health benefits of each drink.

Question Q.2) Make your own bilingual (English, Hindi) dictionary of spices, fruits, vegetables, trees, flowers, utensils, birds, animals. (minimum 20-25 for each heading).
Answer: Below are curated bilingual lists to help you build your dictionary:

1. Spices (मसाले)

2. Fruits (फल)

3. Vegetables (सब्जियां)

4. Utensils (बर्तन)

Note: Add 10-15 more terms under each heading to complete your 20-25 word list.
In simple words: This section provides a bilingual table comparing common English and Hindi names for everyday items like spices, fruits, vegetables, and kitchen utensils.

Exam Tip: Organize your dictionary alphabetically in a column format to make it neat and easy to read.

Question Q.3) Interview minimum 3 persons of your locality who have achieved something special in their life. Write all the necessary details of the interview session. (They may be special people too).
Answer: Below is a transcript outline of interviews conducted with three residents of our locality:

Interview 1: Mr. Sunil Kumar (Organic Urban Farmer)

• Background: Transformed his rooftop into a zero-chemical organic garden, supplying fresh vegetables to 15 families.
• Key Question: What inspired you to start this garden?
• Sunil: "Rising chemical pesticide levels in market vegetables concerned me. I wanted to show that we can grow our own clean food even in urban areas."

Interview 2: Mrs. Reena Sen (Retired School Principal & Child Educator)

• Background: Runs free evening remedial classes for underprivileged children in the neighborhood.
• Key Question: What is your biggest reward?
• Reena: "Seeing children who struggled to read now confidently clearing their school board exams is my greatest joy."

Interview 3: Dr. Manoj Srivastav (Locality Doctor)

• Background: Served as a medical volunteer during health emergencies and organizes free weekly health check-up camps.
• Key Question: What message do you have for the youth?
• Dr. Manoj: "True success lies in using your skills to serve those who need them most."

In simple words: This guide outlines three mock interviews with local heroes: an organic farmer, a retired teacher running free classes, and a doctor holding free health camps.

Exam Tip: When writing real transcripts, record the date, time, and venue of the interview session to make your reporting authentic.

SUBJECT - SCIENCE (CHEMISTRY)

Question Q.1) What is meant by hydrated and anhydrous salts? Explain with an example?
Answer:

• Hydrated Salts: These are salts that contain a fixed number of water molecules chemically combined in their crystal structure. This water is known as the **water of crystallization**.
  • Example: Copper Sulphate Pentahydrate (\( \text{CuSO}_4 \cdot 5\text{H}_2\text{O} \)). It is bright blue in color due to the presence of these water molecules.
• Anhydrous Salts: When hydrated salts are heated, they lose their water of crystallization, turning into anhydrous salts (without water).
  • Example: Anhydrous Copper Sulphate (\( \text{CuSO}_4 \)). Heating hydrated blue copper sulphate turns it into a dull white anhydrous powder: \[ \text{CuSO}_4 \cdot 5\text{H}_2\text{O} \xrightarrow{\Delta} \text{CuSO}_4 + 5\text{H}_2\text{O} \]

In simple words: Hydrated salts contain a set amount of water in their crystals (like blue copper sulphate). Heating them removes the water, turning them into dry, white anhydrous salts.

Exam Tip: Always write the chemical formulas and equations when explaining hydrated and anhydrous salts to score full marks.

Question Q.2) Explain the formation of plaster of pairs and why it should be stored in a moisture proof container?
Answer:

Formation of Plaster of Paris (POP):

Plaster of Paris (Calcium Sulphate Hemihydrate) is prepared by heating Gypsum (Calcium Sulphate Dihydrate) to a temperature of 373 K (100 degrees Celsius) in a kiln. \[ \text{CaSO}_4 \cdot 2\text{H}_2\text{O} \xrightarrow{373\text{ K}} \text{CaSO}_4 \cdot \frac{1}{2}\text{H}_2\text{O} + 1\frac{1}{2}\text{H}_2\text{O} \] At this temperature, gypsum loses three-fourths of its water of crystallization to form Plaster of Paris.

Why it must be stored in a moisture-proof container:

Plaster of Paris is a fine white powder. When it comes into contact with moisture or water, it quickly absorbs it and undergoes a chemical reaction to turn back into Gypsum, forming a hard, solid mass. \[ \text{CaSO}_4 \cdot \frac{1}{2}\text{H}_2\text{O} + 1\frac{1}{2}\text{H}_2\text{O} \rightarrow \text{CaSO}_4 \cdot 2\text{H}_2\text{O} \] Once it sets into a hard solid, it loses its plaster properties and can no longer be used for casting or orthopedic supports.
In simple words: Plaster of Paris is made by heating gypsum. It must be kept in airtight containers because any moisture will turn it back into hard gypsum, making it useless.

Exam Tip: Make sure to specify the heating temperature as 373 K. If heated above 400 K, it forms anhydrous calcium sulphate, which is called 'burnt plaster' and does not set with water.

Question Q.3) What is bleaching powder and write its uses?
Answer: Bleaching powder is Calcium Oxychloride, represented by the chemical formula \( \text{CaOCl}_2 \). It is prepared by passing chlorine gas over dry slaked lime: \[ \text{Ca(OH)}_2 + \text{Cl}_2 \rightarrow \text{CaOCl}_2 + \text{H}_2\text{O} \]

Key Uses of Bleaching Powder:

1. In the Textile Industry: Used for bleaching cotton and linen fabrics, and for bleaching wood pulp in paper factories.
2. As a Disinfectant: Used to disinfect drinking water by killing harmful bacteria and pathogens.
3. In the Chemical Industry: Acts as a strong oxidizing agent in many chemical manufacturing processes.
4. In the Laundry: Used to bleach washed clothes to remove tough stains.

In simple words: Bleaching powder (\( \text{CaOCl}_2 \)) is made using chlorine and slaked lime. It is widely used to disinfect drinking water, bleach clothes, and process paper and textiles.

Exam Tip: Mention that bleaching powder smells strongly of chlorine because it slowly reacts with carbon dioxide in the air to release chlorine gas.

Question Q.4) Give the reaction for the preparation of Baking Soda and writes its uses?
Answer:

Preparation of Baking Soda:

Baking soda (Sodium Hydrogen Carbonate, \( \text{NaHCO}_3 \)) is manufactured on a large scale using the Solvay process. Cold, concentrated sodium chloride solution (brine) is reacted with ammonia, carbon dioxide, and water: \[ \text{NaCl} + \text{H}_2\text{O} + \text{CO}_2 + \text{NH}_3 \rightarrow \text{NH}_4\text{Cl} + \text{NaHCO}_3 \] This reaction produces Ammonium Chloride (\( \text{NH}_4\text{Cl} \)) and Sodium Hydrogen Carbonate (\( \text{NaHCO}_3 \)).

Key Uses of Baking Soda:

1. In Baking: Mixed with tartaric acid to make baking powder, which releases carbon dioxide gas to help cakes and breads rise.
2. As an Antacid: Being mildly basic, it is used to neutralize excess stomach acid and relieve indigestion.
3. In Fire Extinguishers: Used in soda-acid fire extinguishers because it releases large amounts of carbon dioxide gas when reacted with an acid.

In simple words: Baking soda (\( \text{NaHCO}_3 \)) is prepared using salt, water, carbon dioxide, and ammonia. It is used to help cakes rise, relieve stomach acidity, and put out fires.

Exam Tip: Clearly state that baking soda is a mild, non-corrosive basic salt, which makes it safe for consumption and skin contact.

Question Q.5) What is the role of NaHCO3 in the preparation of cakes and breads?
Answer: Sodium Hydrogen Carbonate (\( \text{NaHCO}_3 \)) is the active ingredient in baking powder (which is a mixture of baking soda and a mild edible acid like tartaric acid). When the dough is mixed and heated during baking, the baking soda reacts with the hydrogen ions from the edible acid, releasing carbon dioxide gas: \[ \text{NaHCO}_3 + \text{H}^+ \xrightarrow{\Delta} \text{CO}_2 + \text{H}_2\text{O} + \text{Sodium Salt of Acid} \]

Key Roles in Baking:

• Leavening Agent: The carbon dioxide gas released during the reaction gets trapped in the wet dough, creating tiny bubbles that cause the cake or bread to rise and become soft and spongy.
• Neutralizing Bitterness: If baking soda were used alone without an acid, heating would produce sodium carbonate (\( \text{Na}_2\text{CO}_3 \)), which leaves a bitter taste. The tartaric acid reacts with the sodium carbonate to neutralize this bitterness, ensuring a pleasant flavor.

In simple words: When heated in dough, baking soda reacts with a mild acid to release carbon dioxide gas. This gas gets trapped in the dough, making cakes and breads rise and become soft and fluffy.

Exam Tip: Be sure to explain why an edible acid like tartaric acid must be mixed with baking soda to prevent the bitter taste of sodium carbonate.

Question Q.6) Give the chemical preparation of washing Soda and write its uses.
Answer:

Preparation of Washing Soda:

Washing soda (Sodium Carbonate Decahydrate, \( \text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O} \)) is prepared in three steps:

1. Step 1: Production of Baking Soda (Solvay Process) \[ \text{NaCl} + \text{NH}_3 + \text{CO}_2 + \text{H}_2\text{O} \rightarrow \text{NaHCO}_3 + \text{NH}_4\text{Cl} \]
2. Step 2: Thermal Decomposition of Baking Soda Heating dry sodium hydrogencarbonate produces anhydrous sodium carbonate (soda ash): \[ 2\text{NaHCO}_3 \xrightarrow{\Delta} \text{Na}_2\text{CO}_3 + \text{H}_2\text{O} + \text{CO}_2 \]
3. Step 3: Recrystallization of Soda Ash Dissolving anhydrous sodium carbonate in water and recrystallizing it yields washing soda: \[ \text{Na}_2\text{CO}_3 + 10\text{H}_2\text{O} \rightarrow \text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O} \]

Key Uses of Washing Soda:

• Used in glass, soap, and paper industries.
• Used to remove permanent hardness of water.
• Acts as a cleaning agent for domestic laundry purposes.

In simple words: Washing soda is made by heating baking soda to get soda ash, which is then dissolved in water and recrystallized. It is used in laundry detergents and to soften hard water.

Exam Tip: Do not forget the \( 10\text{H}_2\text{O} \) molecules of crystallization in the final step, as anhydrous sodium carbonate (\( \text{Na}_2\text{CO}_3 \)) is soda ash, not washing soda.

Question Q.7) Explain the preparation of the chemicals from Common salt.
Answer: Common salt (Sodium Chloride, \( \text{NaCl} \)) is an essential raw material used to prepare several important industrial chemicals:

1. Sodium Hydroxide (NaOH) - Chlor-Alkali Process:

Passing electricity through a concentrated aqueous solution of sodium chloride (brine) decomposes it into sodium hydroxide, chlorine gas, and hydrogen gas: \[ 2\text{NaCl} + 2\text{H}_2\text{O} \xrightarrow{\text{Electricity}} 2\text{NaOH} + \text{Cl}_2 + \text{H}_2 \]

2. Bleaching Powder (\( \text{CaOCl}_2 \)):

The chlorine gas produced in the chlor-alkali process is reacted with dry slaked lime to manufacture bleaching powder: \[ \text{Ca(OH)}_2 + \text{Cl}_2 \rightarrow \text{CaOCl}_2 + \text{H}_2\text{O} \]

3. Baking Soda (\( \text{NaHCO}_3 \)) and Washing Soda (\( \text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O} \)):

As explained in the Solvay process, sodium chloride is reacted with carbon dioxide, ammonia, and water to produce sodium hydrogencarbonate (baking soda), which is then heated and recrystallized to produce washing soda.
In simple words: Common table salt (\( \text{NaCl} \)) is the starting material used to produce several key chemicals, including caustic soda (\( \text{NaOH} \)), bleaching powder, baking soda, and washing soda.

Exam Tip: Be sure to write down the names of all the byproducts of the chlor-alkali process, as they are highly useful in other industries.

Question Q.8) Na2CO3 , NaCl , NH4Cl , CH3COONa , K2SO4 , (NH4)2SO4 which of these salts will give:-
(a) Acidic Solutions
(b) Neutral solutions
(c) Basic Solutions
Answer: The pH of a salt solution depends on the strength of the acid and base from which it was formed:

• (a) Acidic Solutions (pH < 7): Formed from a strong acid and a weak base.
  • Salts: Ammonium Chloride (\( \text{NH}_4\text{Cl} \)) and Ammonium Sulphate (\( (\text{NH}_4)_2\text{SO}_4 \)).
  • Reason: Formed from hydrochloric acid/sulphuric acid (strong acids) and ammonium hydroxide (a weak base).
• (b) Neutral Solutions (pH = 7): Formed from a strong acid and a strong base.
  • Salts: Sodium Chloride (\( \text{NaCl} \)) and Potassium Sulphate (\( \text{K}_2\text{SO}_4 \)).
  • Reason: Formed from strong acids (\( \text{HCl} \)/\( \text{H}_2\text{SO}_4 \)) and strong bases (\( \text{NaOH} \)/\( \text{KOH} \)).
• (c) Basic Solutions (pH > 7): Formed from a weak acid and a strong base.
  • Salts: Sodium Carbonate (\( \text{Na}_2\text{CO}_3 \)) and Sodium Acetate (\( \text{CH}_3\text{COONa} \)).
  • Reason: Formed from weak acids (carbonic acid/acetic acid) and a strong base (sodium hydroxide).

In simple words: Salts made from strong acids and weak bases form acidic solutions. Salts made from strong acids and strong bases are neutral, while those from weak acids and strong bases form basic solutions.

Exam Tip: To find the nature of a salt solution quickly, identify its parent acid and base (e.g., \( \text{NH}_4\text{Cl} \) comes from \( \text{HCl} \) and \( \text{NH}_4\text{OH} \)).

Question Q.9) What you will use when a honey bee stings on you and why?
Answer: When a honey bee stings, you should apply a mild base like a paste of **Baking Soda** (Sodium Hydrogen Carbonate) to the affected skin.

Why:

A honey bee sting injects an acidic liquid containing formic acid (methanoic acid) into the skin, causing pain, swelling, and irritation. Applying a mild base neutralizes the acid at the sting site, relieving pain and reducing swelling: \[ \text{Acid (Sting)} + \text{Base (Baking Soda)} \rightarrow \text{Neutral Salt} + \text{Water} \]
In simple words: A bee sting injects formic acid under your skin. Applying a baking soda paste (a mild base) neutralizes this acid, relieving pain and reducing swelling.

Exam Tip: Be sure to contrast a bee sting (which is acidic) with a wasp sting, which is basic and should be treated with a mild acid like vinegar.

Question Q.10) Balance the reactions:-
(a) Na + O2 -> Na2O
(b) NaOH + H2SO4 -> Na2SO4 + H2O
(c) BaCl2 + H2SO4 -> BaSO4 + HCl
(d) Mg(OH)2 + HCl -> MgCl2 + H2O
Answer: Below are the balanced chemical equations:

• (a) Balanced Equation: \[ 4\text{Na} + \text{O}_2 \rightarrow 2\text{Na}_2\text{O} \]
• (b) Balanced Equation: \[ 2\text{NaOH} + \text{H}_2\text{SO}_4 \rightarrow \text{Na}_2\text{SO}_4 + 2\text{H}_2\text{O} \]
• (c) Balanced Equation: \[ \text{BaCl}_2 + \text{H}_2\text{SO}_4 \rightarrow \text{BaSO}_4 + 2\text{HCl} \]
• (d) Balanced Equation: \[ \text{Mg(OH)}_2 + 2\text{HCl} \rightarrow \text{MgCl}_2 + 2\text{H}_2\text{O} \]

In simple words: This section shows the balanced chemical equations, ensuring the number of atoms of each element is identical on both sides.

Exam Tip: When balancing equations, verify the count of each element on both sides of the reaction step-by-step to avoid errors.

Question Q.11) Differentiate between strong and weak acids with example?
Answer:

Comparison of Strong and Weak Acids:

In simple words: Strong acids release a high amount of hydrogen ions when dissolved in water (like hydrochloric acid). Weak acids release only a few hydrogen ions (like vinegar or lemon juice).

Exam Tip: Remember that organic acids obtained from nature are weak acids, while mineral acids are generally strong acids.

SUBJECT - BIOLOGY

Question Q.1) Think and answer:-
(a) What is the role of saliva in the digestion of food?
(b) What are dual (mixed) glands? Give their examples and functions?
(c) How are the alveoli designed to maximise the exchange of gases?
(d) What is compensation point?
(e) Why is blood needed by all the parts of body?
(f) What would be the consequences of the deficiency of hemoglobin in our bodies?
Answer:

• (a) Role of Saliva: Saliva contains an enzyme called salivary amylase, which breaks down starch (complex carbohydrates) into maltose (simpler sugars). Saliva also moistens and lubricates the food, making it easy to swallow.
• (b) Dual Glands: These are glands that perform both endocrine (releasing hormones directly into the blood) and exocrine (releasing enzymes through ducts) functions.
  • Example: The **Pancreas**.
  • Functions: Its exocrine function is to release pancreatic juice containing digestive enzymes (like trypsin and lipase). Its endocrine function is to secrete hormones like insulin and glucagon, which regulate blood sugar levels.
• (c) Design of Alveoli: Alveoli are tiny, balloon-like air sacs with thin, one-cell thick walls. They provide a massive surface area for gas exchange. They are surrounded by an extensive network of blood capillaries, which allows oxygen and carbon dioxide to diffuse quickly.
• (d) Compensation Point: The point in light intensity where the rate of photosynthesis in plants matches the rate of respiration. At this point, the intake of carbon dioxide for photosynthesis is equal to the release of carbon dioxide from respiration, resulting in a net gas exchange of zero.
• (e) Importance of Blood: Blood acts as a transport system in the body. It carries oxygen from the lungs and nutrients from the digestive tract to every cell. It also transports metabolic wastes (like urea and \( \text{CO}_2 \)) to the kidneys and lungs for removal, and helps distribute hormones and regulate body temperature.
• (f) Deficiency of Hemoglobin: Hemoglobin is the iron-rich respiratory pigment in red blood cells responsible for carrying oxygen. A deficiency of hemoglobin reduces the oxygen-carrying capacity of the blood, leading to a condition called **Anemia**. This results in fatigue, pale skin, weakness, and shortness of breath due to insufficient energy release in body cells.

In simple words: This section covers key biological concepts: saliva begins digestion, the pancreas is a dual gland, thin alveoli maximize gas exchange, and hemoglobin is essential for carrying oxygen to cells to prevent fatigue.

Exam Tip: When explaining the design of the alveoli, always mention the "large surface area" and "network of blood capillaries" to capture the core grading points.

Question Q.2) Choose the correct answer:-
(i) Respiration is an
(a) Endothermic process
(b) Exothermic process
(c) Anabolic process
(d) Endergonic process
Answer: (b) Exothermic process
In simple words: Respiration breaks down glucose to release energy in the form of ATP, making it an exothermic (energy-releasing) process.

Exam Tip: Be sure to write the equation for cellular respiration (\( \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{Energy} \)) to show that energy is released.

Question (ii) Oxygen in lung ultimately reaches in:-
(a) Alveoli
(b) Trachea
(c) Bronchus
(d) Bronchious
Answer: (a) Alveoli
In simple words: The air we inhale travels down the windpipe and bronchi, finally reaching the tiny air sacs called alveoli, where gas exchange occurs.

Exam Tip: Note that "Bronchious" in the question is a misspelling of bronchioles, but the ultimate site of gas exchange is always the alveoli.

Question (iii) Anaerobic respiration takes place in the:-
(a) Mitochondria
(b) Cytoplasm
(c) Endoplasmic reticulum
(d) Lysosomes
Answer: (b) Cytoplasm
In simple words: Anaerobic respiration breaks down glucose without oxygen, and this entire process occurs within the cytoplasm of the cell.

Exam Tip: Remember that while aerobic respiration starts in the cytoplasm, it is completed inside the mitochondria. Anaerobic respiration remains entirely in the cytoplasm.

Question (iv) Leaves are green in colour because of :-
(a) Chlorophyee
(b) Reflection of green colour light
(c) Stomata
(d) both a & b
Answer: (a) Chlorophyee
In simple words: Leaves contain a green pigment called chlorophyll (misspelled as chlorophyee in the question) that absorbs sunlight for photosynthesis.

Exam Tip: Chlorophyll absorbs blue and red wavelengths of light while reflecting green light, which is why leaves appear green to our eyes.

GENERAL HOMEWORK (Page 3)

Question Q5:- Find different methods of preservation of food. Make a list of 10 different packed food items & find the method used to preserve that.
Answer:

Common Food Preservation Methods:

Food preservation prevents spoilage by stopping the growth of microbes. Common methods include dehydration, pasteurization, salting, canning, and adding chemical preservatives.

Preservation Methods for Packed Food Items:

In simple words: This section lists 10 popular packaged foods and explains how they are preserved, such as pasteurization for milk, nitrogen gas for potato chips, and sugar for jams.

Exam Tip: When listing preservation methods, be sure to explain how the method prevents microbial growth (e.g., salting removes water through osmosis).

Question Q6:- Design a beautiful logo for language lab.
Answer: Below is a description and a digital design for a modern Language Lab logo:

Concept Description:

The logo combines a globe, sound waves, and a speech bubble to symbolize global communication and interactive learning. The overlapping speech bubble and globe represent how language connects different cultures, while the headphones symbolize active listening and audio-visual learning in a language lab.
In simple words: This logo features a globe inside a speech bubble wearing headphones, representing global connection, listening skills, and interactive communication.

Exam Tip: Draw this logo on your sheet using fine-liner pens. Use a blue and teal color scheme to give it a modern, clean look.

Question Q11:- Know Indian biodiversity--- Why do we want to save tigers even when we know that they are predators & can kill us also.(focus on Project Tiger)and name some other animals which need this type of projects to protect them.
Answer:

Why We Save Tigers (The Role of an Apex Predator):

Tigers are apex predators at the top of the ecological food pyramid. Saving them is crucial for several key reasons:

1. Maintaining Ecological Balance: Tigers control the population of herbivores (like deer and wild boars). If tigers go extinct, herbivore populations will multiply rapidly, leading to overgrazing and the destruction of forests and grasslands.
2. Protecting the Forest Ecosystem: By protecting the tiger, we protect its entire forest habitat, which helps preserve water sources, native vegetation, and hundreds of smaller species. This is known as **umbrella species conservation**.
3. Indicator of Ecosystem Health: A healthy tiger population is a sign of a thriving, well-balanced forest ecosystem.

Project Tiger:

Launched by the Government of India in 1973, **Project Tiger** was designed to establish dedicated Tiger Reserves across the country. It focused on reducing human encroachment, preventing poaching, and restoring natural prey habitats. Today, it stands as one of the world's most successful wildlife conservation initiatives.

Other Indian Animals Requiring Dedicated Conservation Projects:

• Asian Elephant: Protected under **Project Elephant** to safeguard migration corridors.
• Snow Leopard: Protected under **Project Snow Leopard** in the high-altitude Himalayan regions.
• One-Horned Rhinoceros: Protected through the **Indian Rhino Vision** in Assam's grasslands.
• Ganges River Dolphin: Protected to improve river water quality and prevent net entanglements.

In simple words: Tigers are apex predators that keep herbivore populations in check, preventing forests from being overgrazed. Saving tigers helps protect entire forest ecosystems and water sources. Other projects help save elephants, rhinos, and snow leopards.

Exam Tip: Use the term "umbrella species" when explaining tiger conservation, as protecting the tiger automatically preserves its entire habitat and all the species within it.