Maharashtra Board Class 11 Chemistry Chapter 16 in Everyday Life Solutions

1. Choose Correct Option

 

Question A. Oxidative Rancidity is …………….. reaction
(a) addition
(b) substitution
(c) Free radical
(d) combination
Answer: (c) Free radical
In simple words: Oxidative rancidity happens when oxygen reacts with fats and oils through a chain reaction of highly reactive molecules called free radicals, spoiling the food.

🎯 Exam Tip: Remember that rancidity of oils and fats is always initiated by light or oxygen via a free radical mechanism, so look for "free radical" in such questions.

 

Question B. Saponification is carried out by ……………..
(a) oxidation
(b) alkaline hydrolysis
(c) polymerisation
(d) Free radical formation
Answer: (b) alkaline hydrolysis
In simple words: Saponification is the process of making soap by breaking down fats or oils using a strong base like sodium hydroxide.

🎯 Exam Tip: Saponification literally means "soap-making". Always associate soap preparation with the alkaline hydrolysis of esters (fats/oils).

 

Question C. Aspirin is chemically named as ……………..
(a) Salicylic acid
(b) acetyl salicylic acid
(c) chloroxylenol
(d) thymol
Answer: (b) acetyl salicylic acid
In simple words: Aspirin is a common painkiller made by adding an acetyl group to salicylic acid, which is why its chemical name is acetyl salicylic acid.

🎯 Exam Tip: Memorize the chemical names of common household medicines like Aspirin (acetylsalicylic acid) and Paracetamol, as they are frequently asked in exams.

Question D. Find odd one out from the following
(a) dettol
(b) chloroxylenol
(c) paracetamol
(d) trichlorophenol
Answer: (c) paracetamol
In simple words: Paracetamol is a medicine used to reduce pain and fever, whereas the other three are antiseptics used to destroy germs on the skin or surfaces.

🎯 Exam Tip: Remember that antiseptics are applied to living tissues to kill microbes, while analgesics like paracetamol are taken internally to relieve pain.

 

Question E. Arsenic based antibiotic is
(a) Azodye
(b) prontosil
(c) salvarsan
(d) sulphapyridine
Answer: (c) salvarsan
In simple words: Salvarsan is a famous historical medicine containing arsenic that was used to cure a bacterial disease called syphilis.

🎯 Exam Tip: Salvarsan is also known as arsphenamine; remembering its association with arsenic and syphilis treatment is highly important for exams.

 

Question F. The chemical used to slow down the browning action of cut fruit is
(a) \( \text{SO}_3 \)
(b) \( \text{SO}_2 \)
(c) \( \text{H}_2\text{SO}_4 \)
(d) \( \text{Na}_2\text{CO}_3 \)
Answer: (b) \( \text{SO}_2 \)
In simple words: Sulfur dioxide gas stops oxygen from reacting with the cut surface of fruits, keeping them fresh and preventing them from turning brown.

🎯 Exam Tip: Sulfur dioxide (\( \text{SO}_2 \)) is widely used as a food preservative and antioxidant to maintain the color of dried fruits and fresh-cut produce.

 

Question G. The chemical is responsible for the rancid flavour of fats is
(a) Butyric acid
(b) Glycerol
(c) Protein
(d) Saturated fat
Answer: (a) Butyric acid
In simple words: When butter or fat spoils, it releases butyric acid, which gives it a bad, sour smell and taste known as rancidity.

🎯 Exam Tip: Rancidity of butter is specifically caused by the hydrolysis of fats releasing volatile butyric acid, which is a key concept in food chemistry.

 

Question H. Health benefits are obtained by consumption of
(a) Saturated fats
(b) trans fats
(c) monounsaturated fats
(d) All of the options
Answer: (c) monounsaturated fats
In simple words: Monounsaturated fats, like those found in olive oil and avocados, are healthy fats that support heart health.

🎯 Exam Tip: Remember that unsaturated fats (especially monounsaturated) are generally beneficial for health, unlike trans fats and saturated fats.

Explain the Following:

 

Question A. Cooking makes food easy to digest.
Answer: During the cooking process, high polymers of carbohydrates or proteins are hydrolysed to smaller polymeric units. The uncooked food mixture is a heterogeneous suspension which becomes a colloidal matter on cooking. As a result, the constituent nutrient molecules present in cooked food are smaller in size and hence, easier to digest, than the uncooked food. This chemical transformation significantly reduces the workload on our digestive system. Hence, cooking makes food easy to digest.
In simple words: Cooking breaks down large, complex food molecules into smaller, simpler pieces. This makes it much easier for our stomach to digest and absorb the nutrients.

🎯 Exam Tip: Mention key terms like 'hydrolysed', 'smaller polymeric units', and 'colloidal matter' to secure full marks in this explanation.

 

Question B. On cutting some fruits and vegetables turn brown.
Answer:
i. Cutting of fruits and vegetables damage the cells, resulting in release of chemicals.
ii. Depending on the pH of fruits/vegetables, polyphenols are released.
iii. Due to the action of an enzyme, these polyphenols react with oxygen present in the air and get oxidised to form quinones.
Polyphenol + \( \frac{1}{2}\text{O}_2 \)
\( \implies \) Quinone + \( \text{H}_2\text{O} \)
iv. Quinones further undergo reactions including polymerization, which results in browning. This browning reaction is a natural defense mechanism of the plant cells.
In simple words: When fruits are cut, their damaged cells release chemicals that react with oxygen in the air. This chemical reaction creates new dark-colored compounds, turning the cut surface brown.

🎯 Exam Tip: Clearly write down the chemical reaction showing the oxidation of polyphenol to quinone to score maximum marks.

 

Question C. Vitmin E is added to packed edible oil.
Answer:
• Vitamin E is a very effective natural antioxidant.
• The phenolic – OH group present in the structure of vitamin E is responsible for its antioxidant activity.
• Also, the long chain of saturated carbon atoms makes it fat soluble. This unique structure allows it to dissolve easily in oils and protect them from within.
• Therefore, when vitamin E is added to packed edible oil, it prevents the oxidative rancidity of the oil.
In simple words: Vitamin E is a natural protector that easily dissolves in oil and stops it from spoiling or smelling bad when exposed to air.

🎯 Exam Tip: To score full marks, remember to mention both the role of the phenolic -OH group for antioxidant activity and the long carbon chain for fat solubility.

 

Question D. Browning of cut apple can be prolonged by applying lemon juice.
Answer:
• Browning of cut apple is due to the oxidation of polyphenols at a particular pH to quinones, which further undergoes polymerization to form brown coloured tannins.
• This browning reaction can be prolonged or slowed down by using reducing agents or by changing the pH.
• Applying lemon juice (i.e., citric acid) on the cut apple, lowers the pH at the surface of the apple. This prevents the oxidation reaction. This simple kitchen trick effectively deactivates the enzymes responsible for the color change. Thus, browning of cut apple can be prolonged by applying lemon juice.
In simple words: When you cut an apple, exposure to air turns it brown. Applying acidic lemon juice lowers the pH on the surface and stops this browning reaction.

🎯 Exam Tip: Clearly explain how lowering the pH with citric acid inhibits the oxidation of polyphenols to secure maximum marks.

 

Question E. A diluted solution (4.8 % w/v) of 2,4,6-trichlorophenol is employed as antiseptic.
Answer:
• 2,4,6-Trichlorophenol (TCP) is more potent antiseptic than phenol.
• It has low corrosive effects as compared to phenol, if used in lower concentrations. This makes it much safer for application on living tissues and minor wounds.
• Hence, diluted solution (4.8% w/v) of 2,4,6-trichlorophenol is used as antiseptic.
In simple words: TCP is a stronger germ-killer than regular phenol, and in low concentrations, it does not burn or damage the skin.

🎯 Exam Tip: Highlight the comparison with phenol, specifically mentioning TCP's higher potency and lower corrosiveness at low concentrations.

 

Question F. Turmeric powder can be used as antiseptic.
Answer: Turmeric powder contains an active ingredient called curcumin. Curcumin has antiseptic properties; thus, it is used for wound healing or applied on bruise. This traditional remedy has been trusted in households for generations to prevent infections. Hence, turmeric powder can be used as antiseptic.
In simple words: Turmeric contains a special natural compound called curcumin. This compound helps fight germs and heals wounds quickly when applied to cuts or bruises.

🎯 Exam Tip: Always mention 'curcumin' as the active ingredient when explaining the antiseptic properties of turmeric to secure full marks.

 

3. Identify the Functional Groups in the Following Molecule:

 

Question 1. Identify and describe the chemical structures of the following common compounds: Aspirin, Paracetamol, Penicillin, Chloramphenicol, Sulphanilamide, and Glycerin.
Answer: The chemical structures and descriptions of the given compounds are as follows:

• A. Aspirin (Acetylsalicylic acid): It consists of a benzene ring with an acetoxy group (\( -\text{O-CO-CH}_3 \)) and a carboxylic acid group (\( -\text{COOH} \)) attached at adjacent (ortho) positions.
• B. Paracetamol (Acetaminophen): It consists of a benzene ring substituted with a hydroxyl group (\( -\text{OH} \)) at position 1 and an acetamido group (\( -\text{NH-CO-CH}_3 \)) at position 4 (para-position).
• C. Penicillin: It features a core beta-lactam ring fused to a five-membered thiazolidine ring, with a variable acyl side chain (\( \text{R-CO-NH-} \)) and a carboxylic acid group (\( -\text{COOH} \)).
• D. Chloramphenicol: It contains a nitrobenzene ring (\( \text{O}_2\text{N-C}_6\text{H}_4- \)) attached to a propane-1,3-diol backbone with a dichloroacetamide side chain (\( -\text{NH-CO-CHCl}_2 \)).
• E. Sulphanilamide: It consists of a benzene ring with an amino group (\( -\text{NH}_2 \)) at one end and a sulfonamide group (\( -\text{SO}_2\text{NH}_2 \)) at the opposite (para) end.
• F. Glycerin (Glycerol): It is a simple triol compound with a propane backbone where each carbon atom is bonded to a hydroxyl group (\( \text{CH}_2\text{OH-CHOH-CH}_2\text{OH} \)).

In simple words: These are the chemical blueprints of common medicines and chemicals we use daily, like pain relievers (aspirin, paracetamol), antibiotics (penicillin, chloramphenicol), and skin moisturizers (glycerin).

🎯 Exam Tip: Memorize the functional groups of each compound (like the ester in aspirin and amide in paracetamol) as examiners frequently ask to identify these specific groups in structural formulas.

Table of Compounds and Their Functional Groups

No.	Compound	Functional Group Present
i.	Aspirin	Ester group \( (\text{R}-\text{C}(=\text{O})-\text{O}-\text{R}) \) and carboxylic acid group \( (-\text{COOH}) \)
ii.	Paracetamol	Phenolic group \( (-\text{OH}) \) and secondary amide group \( (\text{R}-\text{C}(=\text{O})-\text{NH}-) \)
iii.	Penicillin	Secondary amide group \( (\text{R}-\text{C}(=\text{O})-\text{NH}-) \), tertiary amide group, carboxylic acid group \( (-\text{COOH}) \), and thioether \( (\text{R}-\text{S}-\text{R}) \)
iv.	Chloramphenicol	Nitro group \( (-\text{NO}_2) \), secondary alcoholic group \( (-\text{CH}(\text{OH})-) \), primary alcoholic group \( (-\text{CH}_2\text{OH}) \), secondary amide group \( (\text{R}-\text{C}(=\text{O})-\text{NH}-) \), and halo group (chloro)
v.	Sulphanilamide	Primary amine group \( (-\text{NH}_2) \) and sulphonamide group \( (-\text{SO}_2\text{NH}_2) \)
vi.	Glycerine	Primary alcoholic group \( (-\text{CH}_2\text{OH}) \) and secondary alcoholic group \( (-\text{CH}(\text{OH})-) \)

4. Give Two Differences Between the Following

 

Question A. Disinfectant and antiseptic
Answer: The differences between disinfectants and antiseptics are as follows:

Disinfectant	Antiseptic
Applied to non-living (inanimate) objects like floors, instruments, and drainage systems.	Applied to living tissues such as wounds, cuts, and diseased skin surfaces.
They are toxic to living tissues and are stronger in action.	They are non-toxic to living tissues and do not harm them.
Example: 1% Phenol solution, Chlorine.	Example: Dettol, Bithionol, 0.2% Phenol solution.

Understanding this distinction is crucial for maintaining hygiene in both medical and domestic environments.
In simple words: Antiseptics are safe to use on our skin and wounds to kill germs, while disinfectants are too strong for our skin and are only used to clean non-living things like floors and tables.

🎯 Exam Tip: Always include at least one specific example for both antiseptics and disinfectants, and mention that phenol can act as both depending on its concentration.

Question A. Disinfectants and antiseptics
Answer:

Disinfectants	Antiseptics
1. Disinfectants are applied on non-living surfaces like floors, instruments, sanitary ware, etc. to kill wide range of microorganisms.	1. Antiseptics are applied on the surface of living tissues in order to sterilise them.
2. Disinfectants cannot be applied on wounds.	2. Antiseptics can be directly applied on wounds.
3. p-chloro-o-benzyl phenol	3. Iodine, boric acid, iodoform, dettol, etc.

Understanding these differences helps in choosing the correct chemical agent for hygiene and medical care.
In simple words: Disinfectants are strong chemicals used to clean non-living things like floors, while antiseptics are milder and safe to use on living skin and wounds to kill germs.

🎯 Exam Tip: Remember that the key difference lies in where they are applied: disinfectants on non-living objects and antiseptics on living tissues.

 

Question B. Soap and synthetic detergent
Answer:

Soap	Synthetic detergent
1. Soaps can be broadly classified into two types, i.e., toilet soaps (prepared using KOH) and laundry soaps (prepared using NaOH).	1. Synthetic detergents are of three types, i.e., anionic, cationic and nonionic detergents.
2. Soaps cannot be used in hard water.	2. Synthetic detergents can be used in soft water as well as in hard water.

These differences in chemical structure determine their efficiency and suitability for various cleaning tasks.
In simple words: Soaps are made from natural fats and do not work well in hard water, whereas synthetic detergents are man-made chemicals that can clean effectively in both soft and hard water.

🎯 Exam Tip: Be sure to mention that soaps form scum in hard water, while synthetic detergents do not, which is their main practical advantage.

 

Question C. Saturated and unsaturated fats
Answer:

Saturated fats	Unsaturated fats
1. In saturated fat, long chains of tetrahedral carbon atoms in the fatty acid get closely packed together.	1. In unsaturated fats, the presence of one or more \( \text{C}=\text{C} \) bond in long chains of fatty acids, prevent molecules from packing closely together.

This structural difference explains why saturated fats are typically solid at room temperature while unsaturated fats remain liquid.
In simple words: Saturated fats have straight carbon chains that pack tightly together, making them solid, while unsaturated fats have double bonds that create bends, keeping them liquid.

🎯 Exam Tip: Clearly highlight the presence of double bonds (\( \text{C}=\text{C} \)) in unsaturated fats as the primary structural difference that prevents close packing.

 

Question D. Rice flour and cooked rice
Answer:

Rice flour	Cooked rice
1. Rice flour can be stored for a long period of time. It has a long shelf life.	1. Cooked rice cannot be stored for a longer period of time. It has very short shelf life.
2. Rice flour is uncooked food and hence, it is difficult to digest.	2. Cooked rice is easier to digest.

Rice flour is a versatile ingredient used in many traditional recipes, whereas cooked rice is ready for immediate consumption.
In simple words: Rice flour is dry and uncooked, so it lasts a long time but is hard to digest. Cooked rice has water in it, so it spoils quickly but is very easy for our bodies to digest.

🎯 Exam Tip: Always present comparison questions in a neat tabular format with corresponding points aligned horizontally to score full marks.

 

Question 5. Match the pairs.

A group	B group
A. Paracetamol	a. Antibiotic
B. Chloramphenicol	b. Synthetic detergent
C. BHT	c. Soap
D. Sodium stearate	d. Antioxidant
	e. Analgesic

Answer:
A – e
B – a
C – d
D – c
These chemical compounds are classified based on their specific therapeutic or industrial applications.
In simple words: This matches different everyday chemical substances with their correct uses, like matching paracetamol to pain relief (analgesic) and soap to sodium stearate.

🎯 Exam Tip: Write the matching pairs directly opposite to each other in the final answer sheet rather than drawing criss-cross lines.

 

Question 6. Name two drugs which reduce body pain.
Answer: Aspirin and paracetamol are the two drugs that reduce body pain. These medications work by blocking chemical messengers in the brain that signal pain.
In simple words: Aspirin and paracetamol are common medicines used to stop or reduce pain in our body.

🎯 Exam Tip: Always mention both aspirin and paracetamol as standard examples of pain-relieving drugs (analgesics) to secure full marks.

 

7. Explain With Examples

 

Question A. Antiseptics
Answer:
i. Antiseptics are used to sterilise surfaces of living tissue when the risk of infection is very high, such as during surgery or on wounds. These substances prevent the growth of disease-causing microorganisms without harming the living tissue.
ii. Commonly used antiseptics include inorganics like iodine and boric acid or organics like iodoform and some phenolic compounds.

e.g.
• Tincture of iodine (2-3% solution of iodine in alcohol-water mixture) and iodoform serve as powerful antiseptics and is used to apply on wounds.
• A dilute aqueous solution of boric acid is a weak antiseptic used for eyes.
• Various phenols are used as antiseptics. A dilute aqueous solution of phenol (carbolic acid) is used as antiseptic; however, phenol is found to be corrosive in nature. Many chloro derivatives of phenols are more potent antiseptics than the phenol itself. They can be used with much lower concentrations, which reduce their corrosive effects.
• Two of the most common phenol derivatives in use are trichlorophenol (TCP) and chloroxylenol (which is an active ingredient of antiseptic dettol).
• Thymol obtained from oil of thyme (a spice plant) has excellent non-toxic antiseptic properties.
In simple words: Antiseptics are mild chemicals applied to living tissues, like cuts or wounds, to kill germs and prevent infections.

🎯 Exam Tip: When explaining antiseptics, always include common examples like tincture of iodine or dilute boric acid to demonstrate a complete understanding.

 

Question B. Disinfectant
Answer:
• Disinfectants are non-selective antimicrobials. Unlike antiseptics, they are typically applied to non-living objects like floors and instruments because they can be too harsh for living tissues.
• They kill a wide range of microorganisms including bacteria.
In simple words: Disinfectants are strong chemicals used to kill germs on non-living surfaces like floors, tiles, and sinks.

🎯 Exam Tip: Clearly distinguish between antiseptics (used on living tissues) and disinfectants (used on non-living surfaces) to avoid losing marks.

 

Question C. Cationic detergents
Answer: Cationic detergents: These are quaternary ammonium salts having one long chain alkyl group. They possess germicidal properties and are relatively expensive to manufacture.
e.g. Ethyltrimethylammonium bromide: \( [\text{CH}_3(\text{CH}_2)_{15} - \text{N}^+(\text{CH}_3)_3]\text{Br}^- \)
In simple words: Cationic detergents are cleaning agents where the active part has a positive charge, and they are often used to kill germs.

🎯 Exam Tip: Remember that cationic detergents are quaternary ammonium salts with a positive charge on the nitrogen atom, which makes them highly useful as germicides.

 

Question D. Anionic detergents
Answer: Anionic detergents: These are sodium salts of long chain alkyl sulphonic acids or long chain alkyl substituted benzene sulphonic acids. They are widely used in household cleaning products like laundry powders.
e.g. Sodium lauryl sulphate: \( \text{CH}_3(\text{CH}_2)_{10}\text{CH}_2\text{OSO}_3^-\text{Na}^+ \)
In simple words: Anionic detergents have a negatively charged active part and are the most common type of soap-free cleaners we use at home.

🎯 Exam Tip: Clearly mention that the hydrophilic part in anionic detergents is negatively charged, usually containing a sulphate or sulphonate group.

 

Question E. Non-ionic detergents
Answer: Nonionic detergents: These are ethers of polyethylene glycol with alkyl phenol or esters of polyethylene glycol with long chain fatty acid. They do not contain any ionic charges in their chemical structure.
e.g.
a. Nonionic detergent containing ether linkage: \( \text{C}_9\text{H}_{19}-\text{C}_6\text{H}_4-\text{O}-(\text{CH}_2\text{CH}_2\text{O})_n\text{CH}_2\text{CH}_2\text{OH} \) (where \( -\text{C}_6\text{H}_4- \) represents a benzene ring)
b. Nonionic detergent containing ester linkage: \( \text{CH}_3(\text{CH}_2)_{16}-\text{COO}(\text{CH}_2\text{CH}_2\text{O})_n\text{CH}_2\text{CH}_2\text{OH} \)
In simple words: Non-ionic detergents do not have any electrical charge on their molecules and are commonly used in liquid dishwashing soaps.

🎯 Exam Tip: Highlight that non-ionic detergents do not dissociate into ions in water, and are formed by the reaction of alcohols or phenols with ethylene oxide.

 

Question 8. Explain : mechanism of cleansing Action of soap with flow chart.
Answer: Soap molecules consist of two parts: a long hydrocarbon chain which is hydrophobic (water-repelling) and a polar carboxylate group which is hydrophilic (water-attracting). When soap is dissolved in water, it forms a colloidal dispersion of spherical aggregates called micelles. The hydrophobic tails cluster together in the center to avoid water, while the hydrophilic heads point outward into the water. When dirty clothes are soaked, the hydrophobic tails dissolve in the grease or oil on the fabric, trapping the dirt inside the micelle. Upon agitation, these micelles are pulled away into the water, carrying the dirt with them.

Flow Chart of Cleansing Action:
• Soap is dissolved in water and dissociates into \( \text{RCOO}^- \) and \( \text{Na}^+ \) ions.
• Hydrophobic tails (\( \text{R}- \)) attach to the grease/oil/dirt on the fabric.
• Hydrophilic heads (\( -\text{COO}^- \)) remain pointing outward into the water.
• Micelles are formed, trapping the grease/dirt at the center.
• Mechanical agitation (rubbing or washing) pulls the micelles away from the fabric.
• The grease/dirt is suspended in water as an emulsion and is washed away with water.
In simple words: Soap has one end that loves water and another end that loves oil. The oil-loving end grabs onto the dirt, while the water-loving end pulls it into the water when we rinse.

🎯 Exam Tip: Draw a clear distinction between the hydrophobic and hydrophilic parts of the soap molecule, and list the steps of micelle formation sequentially to score full marks.

Mechanism of Cleansing Action of Soap

• Oil/fat/grease on surface
• Soap dissolves in water
• Hydrophilic polar head dissolves in water / Hydrophobic nonpolar tail dissolves in oil/fat/grease
• Nonpolar tail is directed towards central oily drop while polar head is directed towards water
• Micelles of soap molecules are formed around oil/fat/grease
• Micelles get removed on washing the surface

 

Question 9. What is meant by broad spectrum antibiotic and narrow spectrum antibiotics?
Answer: Antibiotics which are effective against wide range of bacteria are known as broad spectrum antibiotics, while antibiotics which are effective against one group of bacteria are known as narrow spectrum antibiotics. This classification helps doctors choose the most effective treatment for specific bacterial infections.
In simple words: Broad-spectrum antibiotics can fight many different types of bacteria, while narrow-spectrum ones target only a specific group of bacteria.

🎯 Exam Tip: Clearly distinguish between 'wide range' and 'one group' to secure full marks in this definition.

 

10. Answer in One Sentence

 

Question A. Name the painkiller obtained from acetylation of salicyclic acid.
Answer: Aspirin is the pain killer obtained from acetylation of salicylic acid. It is also widely used to reduce fever and inflammation.
In simple words: Aspirin is a common pain relief medicine made by chemically modifying salicylic acid.

🎯 Exam Tip: Remember that aspirin is the chemical product of acetylating salicylic acid; spelling 'aspirin' correctly is key.

 

Question B. Name the class of drug often called as painkiller.
Answer: Analgesics are the class of drug often called as painkiller. They work by blocking pain signals to the brain.
In simple words: Analgesics are medicines specifically used to relieve pain.

🎯 Exam Tip: Use the term 'analgesics' precisely when asked for the class of pain-relieving drugs.

 

Question C. Who discovered penicillin?
Answer: Alexander Fleming discovered penicillin. This groundbreaking discovery in 1928 marked the beginning of modern antibiotics, saving millions of lives worldwide.
In simple words: Penicillin, the world's first effective antibiotic, was discovered by a scientist named Alexander Fleming. It is used to fight harmful bacterial infections.

🎯 Exam Tip: Remember to write the full name "Alexander Fleming" and spell "penicillin" correctly to secure full marks.

 

Question D. Draw the structure of chloroxylenol and salvarsan.
Answer: The chemical structures are described below:
Structure of chloroxylenol:

• Central benzene ring
• Hydroxyl group (-\(\text{OH}\)) at position 1
• Methyl groups (-\(\text{CH}_3\)) at positions 3 and 5
• Chlorine atom (-\(\text{Cl}\)) at position 4

Structure of salvarsan:

• Two benzene rings linked together
• Arsenic-arsenic double bond (\(\text{As}=\text{As}\)) connecting the rings
• Each ring contains one amine group (-\(\text{NH}_2\)) and one hydroxyl group (-\(\text{OH}\))

These structures represent key antiseptic and antimicrobial agents used in medicine.
In simple words: Chloroxylenol is a benzene ring with one OH, one Cl, and two methyl groups. Salvarsan consists of two benzene rings joined by a double bond between two arsenic atoms, with OH and NH2 groups attached.

🎯 Exam Tip: Practice drawing these structures carefully, paying close attention to the positions of the functional groups on the benzene rings.

 

Question E. Write molecular formula of Butylated hydroxy toulene.
Answer: Molecular formula of butylated hydroxytoluene is \(\text{C}_{15}\text{H}_{24}\text{O}\). This compound is widely used as an antioxidant food additive to prevent spoilage.
In simple words: The chemical formula for butylated hydroxytoluene (BHT) is \(\text{C}_{15}\text{H}_{24}\text{O}\), meaning it contains 15 carbon atoms, 24 hydrogen atoms, and 1 oxygen atom.

🎯 Exam Tip: Double-check the subscripts in the molecular formula \(\text{C}_{15}\text{H}_{24}\text{O}\) to avoid simple calculation errors.

 

Question F. What is the tincture of iodine ?
Answer: Tincture of iodine is a 2-3% solution of iodine in alcohol-water mixture. It is commonly applied to wounds as a powerful antiseptic to prevent infection.
In simple words: Tincture of iodine is a liquid mixture made of a small amount of iodine dissolved in alcohol and water, used to clean cuts and wounds.

🎯 Exam Tip: Always mention the specific percentage range (2-3%) and the solvent mixture (alcohol-water) to get full marks.

 

Question G. Draw the structure of BHT.
Answer: The chemical structure of BHT (Butylated Hydroxytoluene) is described below:

• Central phenol ring (benzene ring with an -\(\text{OH}\) group at position 1)
• Two bulky tert-butyl groups [-\(\text{C(CH}_3)_3\)] attached at positions 2 and 6
• A methyl group (-\(\text{CH}_3\)) attached at position 4

This specific arrangement of groups helps it act as an effective antioxidant by stabilizing free radicals.
In simple words: BHT has a central ring with an OH group at the top, a methyl group at the bottom, and two large butyl groups on the left and right sides.

🎯 Exam Tip: When describing or drawing BHT, ensure the tert-butyl groups are placed symmetrically on both sides of the hydroxyl (-\(\text{OH}\)) group.

 

Question I. Write a chemical equation for saponification.
Answer: The chemical equation for saponification is represented as: \[ \begin{matrix} \text{CH}_2\text{-O-CO-R} \\ | \\ \text{CH-O-CO-R} \\ | \\ \text{CH}_2\text{-O-CO-R} \end{matrix} + 3\text{NaOH} \xrightarrow{\text{saponification}} \begin{matrix} \text{CH}_2\text{OH} \\ | \\ \text{CHOH} \\ | \\ \text{CH}_2\text{OH} \end{matrix} + 3\text{R-COONa} \] Where a triglyceride (fat or oil) reacts with sodium hydroxide to produce glycerol and soap (sodium salt of fatty acid).
In simple words: Saponification is the chemical process of making soap by heating fats or oils with a strong base like sodium hydroxide.

🎯 Exam Tip: Make sure to write the names of the reactants (Fat/Oil, Sodium Hydroxide) and products (Glycerol, Soap) below their respective chemical formulas to score full marks.

 

Question J. Write the molecular formula and name of the given chemical structure:
(Structure of 2-acetoxybenzoic acid)
Answer:
Molecular formula: \( \text{C}_9\text{H}_8\text{O}_4 \)
Name: Aspirin
In simple words: The given chemical structure represents Aspirin, a common medicine used to relieve pain and reduce fever, which has the molecular formula \( \text{C}_9\text{H}_8\text{O}_4 \).

🎯 Exam Tip: Memorize both the common name (Aspirin) and the molecular formula \( \text{C}_9\text{H}_8\text{O}_4 \) as they are frequently asked in exams.

11. Answer the Following

 

Question A. Write two examples of the following.
a. Analgesics
c. Antiseptics
d. Antibiotics
Answer:
a. Analgesics: Aspirin, Paracetamol
c. Antiseptics: Chloroxylenol (Dettol), Tincture of iodine
d. Antibiotics: Penicillin, Tetracycline
In simple words: Analgesics are medicines that relieve pain, antiseptics prevent infection on cuts and wounds, and antibiotics kill harmful bacteria inside our body.

🎯 Exam Tip: Always write clear, standard examples like Paracetamol and Penicillin which are easy to remember and universally accepted by examiners.

Question e. Disinfectant
Answer:

No.	Drug type	Examples
i.	Analgesics	Aspirin, paracetamol
ii.	Antiseptics	Dettol, thymol
iii.	Antibiotics	Penicillin, sulphapyridine
iv.	Disinfectant	Phenol, p-Chloro-o-benzyl phenol

In simple words: This table lists different types of medicines, such as painkillers and antiseptics, along with common everyday examples of each.

🎯 Exam Tip: Memorize at least two examples for each drug class as they are frequently asked in match-the-following or one-word answer questions.

 

Question B. What do you understand by antioxidant?
Answer:
• An antioxidant is a substance that delays the onset of oxidant or slows down the rate of oxidation of foodstuff.
• It is used to extend the shelf life of food.
• Antioxidants react with oxygen-containing free radicals and thereby prevent oxidative rancidity.
• e.g. Vitamin E is a very effective natural antioxidant.
In simple words: Antioxidants are substances added to food to stop them from reacting with oxygen and spoiling, which helps them stay fresh for a longer time.

🎯 Exam Tip: Always include a real-world example like Vitamin E when defining antioxidants to secure full marks.

 

Question. Activity: Collect information about different chemical compounds as per their applications in day-to-day life.
Answer:

No.	Chemical compound	Applications
i.	Vinegar (\( \text{CH}_3\text{COOH} \))	Preservation of food, salad dressing, sauces, etc.
ii.	Magnesium hydroxide [\( \text{Mg(OH)}_2 \)]	Common component of antacids (used to relieve heartburn, acid indigestion and stomach upset.)
iii.	Baking soda (\( \text{NaHCO}_3 \))	Cooking, antacid, toothpaste, etc.

In simple words: Many chemicals we use daily have important jobs, like vinegar preserving food, baking soda helping in cooking, and magnesium hydroxide curing stomach aches.

🎯 Exam Tip: Be sure to write the correct chemical formulas alongside the common names of these daily-use compounds to show a strong understanding.

11th Chemistry Digest Chapter 16 Chemistry in Everyday Life Intext Questions and Answers

Can You Recall? (Textbook Page No. 261)

 

Question i. What are the components of balanced diet?
Answer: Carbohydrates, proteins, lipids (fats and oil), vitamins, minerals and water are the components of balanced diet. A proper balance of these nutrients ensures the smooth functioning of all bodily systems.
In simple words: A balanced diet contains all the essential nutrients like carbs, proteins, fats, vitamins, and minerals that our body needs to stay healthy.

🎯 Exam Tip: Remember to list all six major components—carbohydrates, proteins, lipids, vitamins, minerals, and water—to secure full marks.

 

Question ii. Why is food cooked? What is the difference in the physical states of uncooked and cooked food?
Answer:
• Food is cooked in order to make it easy to digest.
• Also, the raw or uncooked food may contain harmful microorganisms which may cause illness. Cooking of food at high temperature kills most of these microorganisms.
• Raw/uncooked food materials like dried pulses, vegetables, meat, etc. are hard and thus, not easily chewable while cooked food is soft and tender, therefore, easily chewable. Cooking also enhances the flavor and aroma of the food, making it more appetizing.
In simple words: Cooking makes food soft, easy to chew, and easy to digest. It also kills harmful germs, making the food safe to eat.

🎯 Exam Tip: Structure your answer into two parts: first explain why we cook food (digestion and safety), and then compare the physical states (hard vs. soft).

 

Question iii. What are the chemicals that we come across in everyday life?
Answer: Detergents, shampoos, medicines, various food flavours, food colours, etc. are different types of chemicals that we come across in everyday life. Even the salt and sugar we use daily are chemical compounds.
In simple words: We use many chemicals every day, such as soaps, medicines, food colors, and cleaning products.

🎯 Exam Tip: Provide everyday examples like soaps, detergents, and food preservatives to make your answer practical and complete.

Just Think (Textbook Page No. 261)

 

Question i. Why is food stored for a long time?
Answer: Food (like various cereals, pulses, pickles) is stored for a long time to make it available in all seasons. This practice helps prevent wastage and ensures a steady supply of nutrients throughout the year.
In simple words: We store food so that we can eat our favorite fruits, vegetables, and grains even when they are not growing in that season.

🎯 Exam Tip: Mention "availability in all seasons" as it is the key keyword examiners look for in this answer.

 

Question ii. What methods are used for preservation of food?
Answer: Various physical and chemical methods are used for preservations of food.
• Physical methods like, addition of heat, removal of heat, removal of water, irradiation, etc., are used in order to preserve food.
• Chemical methods like, addition of sugar, salt, vinegar, etc. are employed for preservation of food. These substances act as natural barriers against bacterial growth.
In simple words: We can preserve food physically by heating, freezing, or drying it, or chemically by adding things like salt, sugar, and vinegar to stop germs from growing.

🎯 Exam Tip: Clearly categorize your answer into physical and chemical methods to score full marks.

 

Question iii. What is meant by quality of food?
Answer: Food quality can be described in terms of parameters such as flavour, smell, texture, colour and microbial spoilage. High-quality food must be safe to consume and free from harmful contaminants.
In simple words: Food quality means how good the food is based on how it looks, smells, tastes, feels, and whether it is fresh and safe to eat.

🎯 Exam Tip: Remember to list all five parameters: flavour, smell, texture, colour, and microbial spoilage to get full marks.

 

Can You Recall? (Textbook Page No. 263)

 

Question i. How is Vanaspati ghee made?
Answer: Vanaspati ghee is prepared by hydrogenation of oils. Hydrogen gas is passed through the oils at about 450 K in the presence of nickel catalyst to form solid edible fats like vanaspati ghee. This chemical process converts liquid unsaturated fats into solid saturated fats.
\( \text{Vegetable oil (Unsaturated)} + \text{H}_2 \xrightarrow[\text{450 K}]{\text{Ni}} \text{Solid fat (Vanaspati ghee) (Saturated)} \)
In simple words: Vanaspati ghee is made by passing hydrogen gas through liquid vegetable oil at a high temperature using nickel to turn it into a solid fat.

🎯 Exam Tip: Always write the chemical equation along with the temperature (450 K) and catalyst (nickel) to secure maximum marks.

 

Question ii. What are the physical states of peanut oil, butter, animal fat, Vanaspati ghee at room temperature?
Answer: At room temperature, peanut oil is in a liquid state, whereas butter, animal fat, and Vanaspati ghee are in solid or semi-solid states. This difference in physical state is primarily due to the level of saturation in their fatty acid chains.
In simple words: At normal room temperature, peanut oil is a liquid, while butter, animal fat, and Vanaspati ghee are solid or semi-solid.

🎯 Exam Tip: Clearly distinguish between the liquid state of the oil and the solid/semi-solid states of the fats.

Example	Physical state
Peanut oil	Liquid
Butter	Semi-solid
Animal fat	Solid/semi-solid
Vanaspati ghee	Solid/semi-solid

Can You Tell? (Textbook Page No. 264)

 

Question 1. When is an antipyretic drug used?
Answer: An antipyretic drug is used to reduce fever (that is, it lowers body temperature when a fever is present). It helps bring comfort to a person suffering from high body temperature.
In simple words: An antipyretic is a medicine used to lower your body temperature when you have a fever.

🎯 Exam Tip: Remember that 'pyretic' relates to fever, so 'antipyretic' means against fever. Mentioning that it lowers body temperature is key to scoring full marks.

 

Question 2. What type of medicine is applied to a bruise?
Answer: Antiseptic such as tincture of iodine is applied on a bruise in order to prevent the exposed living tissue from getting infected. This helps the wound heal safely without complications.
In simple words: We apply an antiseptic like iodine on a bruise to kill germs and stop the cut from getting infected.

🎯 Exam Tip: Always name a specific example like tincture of iodine when answering questions about antiseptics applied to wounds.

 

Question 3. What is meant by a broad spectrum antibiotic?
Answer: Antibiotics which are effective against wide range of bacteria are known as broad spectrum antibiotic. They are highly useful when the specific type of bacteria causing the infection is not yet identified.
In simple words: A broad-spectrum antibiotic is a strong medicine that can fight and kill many different types of bacteria at the same time.

🎯 Exam Tip: Use the phrase "wide range of bacteria" as it is the core definition that examiners look for.

 

Question 4. What is the active principle ingredient of cinnamon bark?
Answer: Cinnamaldehyde is the principle active ingredient of cinnamon bark. This organic compound gives cinnamon its characteristic flavor and aroma.
In simple words: Cinnamaldehyde is the main natural chemical inside cinnamon bark that gives it its unique smell and taste.

🎯 Exam Tip: Be careful with the spelling of 'Cinnamaldehyde' to avoid losing marks in one-word or short-answer questions.

Can You Tell? (Textbook Page No. 268)

 

Question i. Can we use the same soap for bathing as well as cleaning utensils or washing clothes? Why?
Answer: No, we cannot use the same soap for bathing as well as cleaning utensils or washing clothes due to the following reasons:

• Chemical composition of each type of soap or cleansing material is different.
• Nature, acidity, texture, reactivity towards water (i.e., hard water or soft water), reactivity towards microorganisms, and stains are different for each type of soap.
• Depending on these qualities, soaps are classified and used accordingly. For example, bathing soaps are formulated to be much gentler on human skin to prevent irritation. e.g. pH of soaps used for bathing purpose is different than that of the soap which is used for cleaning utensils.

Thus, we cannot use the same soap for bathing as well as cleaning utensils or washing clothes.
In simple words: Different soaps are made for different jobs. Bathing soap is gentle for our skin, while laundry or utensil soap is much stronger to remove tough grease and dirt.

🎯 Exam Tip: Clearly mention the difference in pH and chemical composition to secure full marks in this question.

 

Question ii. How will you differentiate between soaps and synthetic detergent using borewell water?
Answer: Borewell water is hard water. Soaps and synthetic detergents react differently with hard water.
1. Soap: Soaps are insoluble in hard water. Borewell water (hard water) contains \( \text{Ca}^{2+} \) and \( \text{Mg}^{2+} \) ions. Soaps react with these ions to form insoluble magnesium and calcium salts of fatty acids. These salts precipitate out as a gummy substance or form scum, which reduces their cleansing efficiency.
2. Synthetic detergents: Synthetic detergents can be used in hard water as well. They contain molecules (components) which form soluble calcium and magnesium salts. Thus, soaps will form scum in borewell water but synthetic detergents will not.
In simple words: Borewell water has minerals that make soap form a sticky, useless scum instead of bubbles. Synthetic detergents don't get affected by these minerals and can easily create lather to clean things.

🎯 Exam Tip: Remember to write the chemical symbols \( \text{Ca}^{2+} \) and \( \text{Mg}^{2+} \) correctly, as examiners look for these specific ions when grading hard water questions.