CBSE Class 12 Value Based Questions - Chemistry Based on CBSE and NCERT guidelines. Value based questions are now being given in exams to promote morals and values in students, Students should read and understand the following VBQs to get better understanding and score good marks in exams
SAMPLE VALUE BASED QUESTIONS. (Class XII).
1. Ravi went to a mall to pickup ‘Ready to eat’ food packets; noticed following labels on different food packets.
Permitted Preservatives; Permitted anti-oxidants; Permitted preservatives added added anti-oxidants added.
Packet : A Packet : B Packet : C
a) Which packet would Ravi prefer, and why?
b) What are the values associated with Ravi’s selection?
2. Rita takes sugar while Renu prefers Aspartame in soft drinks for flavour.
a) What is that Renu trying to avoid?
b) What is the probable deficiency in Renu?
c) What are the values that you notice in Renu’s preference?
3. Raju was struggling from stomach ache because of hyper acidity condition. His friend, Ramesh offered him ‘Soda water’ (Aqueous NaHCO3), While Ratan wanted Raju to take ‘Gelusil’ (Aluminium hydroxide gel).
a) Should Raju follow Ramesh’s advice or Ratan’s?
b) What is the advantage of one medicine over the other?
c) What are the values associated with the three friends’ reactions?
4. Reetu wanted to buy milk cup for her son of 3-4 years of age; but was unable to decide between cup made of porcelain and melamine, since both looked colourful and decorative on the rack. She sought the opinion of her younger brother, a student of XII standard.
a) Which cup would the young man select, and why?
b) What are the values associated with his selection of the specific material?
5. Rajesh went to textile shop with his mother to purchase dress material for his school uniform. Rajesh wanted pure cotton fabric which looked bright, while mother insisted on blended fabric with 67% terylene.
a) In your opinion, who is right?
b) What are the monomers of Terylene?
c) What are the values involved in the selection of the fabric?
6. The teacher fixed five cards on the flannel board that marked A, T, C, U, G, pick up cards that indicate bases that are not common to all nucleic acids.
a) Which cards would Rakesh pick from the five?
b) Of the nucleic acids picked by Rakesh, which does not form hydrogen bonding with other nucleic acids?
c) What are the values involved in this exercise?
7. Mrs.Renuka was worried about her daughter not eating properly even though her favourite dishes are made, and shows very small growth in last six months.
a) Which vitamin deficiency may be there in the girl child?
b) Give chemical name of the vitamin deficient in the girl child.
c) What are the values associated with this observation?
8. Ramesh noticed that chloroacetic acid [ Cl-CH2-COOH ] and Alanine [ CH3-CH(NH2)-COOH ] have comparable molar masses but exhibited different melting points and large difference of solubility levels in water.
a) Which of the two would have shown higher melting point and better solubility in water, why?
b) Identify the values associated with his observations.
9. CoCl3.4NH3 precipitates silver chloride with AgNO3(aq) reacting in equimolar amounts, though it has three moles of chlorides per mole. Further the compound was exhibiting different colours when prepared at different times – some times green and some times violet.
a) Give IUPAC name of the compound.
b) Why does it exhibit different colours?
c) What are the values that can be attached with the observations?
10. Sudha’s mother received a phone call on Monday morning from a close relative stating that three of them would be coming over for lunch. Sudha’s mother noticed that she did not have enough curd to serve the guests. Sudha a class XII student suggested that her mother could warm the milk from the refrigerator or keep it under direct sunlight and curdle it.
a) Why do you think Sudha suggested the above methods?
b) Will it be helpful if her mother followed Sudha’s suggestion?
c) What values are associated with Sudha’s suggestion?
11. Mohan was a regular late comer to School. His Class teacher found that his mother was cooking the traditional way in open vessels to prepare lunch for her family in the morning . Teacher suggested that his mother buys a pressure cooker that can be used for cooking.
a) Why did the teacher suggest mohan to buy a pressure cooker?
b) How would be helpful for Mohan’s mother?
c) What values are associated with the teacher’s suggestion?
12. Teacher asked two Students ‘A’ and ‘B’ to demonstrate the reaction between Aluminium and dilute Sulphuric acid to the class. She provided the following chemicals for the experiment: Al foil, Al powder & dilute Sulphuric acid. Student A chose Al foil & dilute Sulphuric acid. Student B chose Al powder & dilute Sulphuric acid.
a) Who do you has made the correct choice of chemicals?
b) Give a reason to justify the correct choice.
c) What value do you associate with the above?
13. Geetha decided to make her bread at home. She bought four main and basic ingredients in the making of bread and they were yeast, flour, salt and water.
a) Do you think she bought what was essential?
b) What is the role of yeast here?
c) What value do you associate with the above?
14. A child refused to take cold lemon jice with crystalline sugar but prefer to take with powdered sugar.
a) What is the effect of Temperature on solubility?
b) Why powdered sugar dissolve in water at a faster rate than crystalline sugar.
c) Which values were kept in mind in this activity?
15. Geetha has prepared home made ice-cream, but her sister Swetharefused to take it after two days.
a) Mention state of dispersed phase and dispersed medium of ice-cream.
b) Why Swetha refused to take home made icecream after 2 days?
c) Mentio the value associated with the above process.
16. Ramesh went to Cinema theatre when it was raining heavily in a car and met with an accident due to unbalanced driving with hindered beam of light.
a) Define Tyndall effect.
b) Ramesh met with an accident. Give Scientific reason?
c) Mention the value associated with the above situation.
17. Mohan and Rahul are good friends, they went to attend a marriage function with a neat dress. Unfortunately there, a sweet dish fell on their shirts and made an oil stain which Mohan washed with water but Rahul washed with soap.
a) What is CMC?
b) Why Rahul shirt looks neat but Mohan shirt looks dirt even after washing?
c) Write the value asociated with above incident.
18. Gita regularly cleans her Artist father’s Metal table with an Organic liquid given by her father due to this regular activity she had eye irritation.After few months she eventually losses vision in one of her eye.
a) What is the effect of chlorination in the presence of Sunlight on Methane?
b) Why did Gita lose her eye sight?
c) List the values associated with the above problem.
19. A farmer cultivating his land near the village pond was also drawing water from it for irrigation. He used insecticide excessively to protect his crops and improve the harvest, Over a period of time his agricultural growth improved vastly. But the pond lost its aquatic life.
a) Draw the structure / IUPAC name of the compound used as an insecticide but not a pesticide..
b) Contrast the activity in plants and aquatic life with insecticide.
c) What value got expressed in students suggestions?
20. Sneha sitting behind her father in motor bike was studying with high concentration while her father was driving. She unknowingly put her foot into the silencer got burned. She was treated in a hospital with a yellow creamy antiseptic which eventually left violet colouration on the skin.
a) Identify the compound and give equation to identify Methyl Ketone.
b) What is the lesson learnt by Sneha after her accident?
21. An anesthetic bottle left on the window side of the operation theatre for a few days. It was exposed to Sun and rain. another doctor used the same bottle on one of his patients and found the patient having severe vomiting and stomach poisioning.
a) Identify the compound. Give relevant equation as to its action.
b) What are the values to be kept in mind while using drugs.
22. A mother brought her 2 year old child to a clinic with a complaint that the child would not stop crying and was profusely vomiting. The doctornoticed the child shirt colar colour was faded.
a) Why dyes are coloured? Give 2 reasons?
b) What is coupling reaction? Give equation
c) What are the values involved in this?
23. Ram & Shyam are good friends, from 2 different localities. Ram used to go to cake point which used a colour light as insect attractants, but Shyam used to go to a way side XYZ bakery . Shyam was affected with poor health and ulcer in the stomach and admitted in the hospital. While Ram stayed healthy.The Doctor diagonised and found Shyam’s poor health due to poor quality of the food .
a) How do you distinguish primary and secondary amine?
b) Which organic compound is used as insect attractants?
c) What is the lesson learnt by Shyam from Ram?
24. A fruit seller bought oranges in the wholesale market and had emptied the sack full of it on his hand cart; the fruits were spread haphazardly all over the cart, some rolling off and some heaped up precariously.
a) As a student of chemistry, how will help him organize the fruits to make it attractive for the buyer as well as easy for him to handle without the fruits rolling off the cart?
b) What were the concepts you applied in this situation. What values do you learn?
25. Ram’s dentist prescribed a fluoride tooth paste for his tooth decay; the same dentist asked Rani’s father to send the water sample from their household for testing, to check if the fluoride content in it was excess,while treating her mottled teeth.
a) How would you explain this contradiction?
b) What is the value associated?
26. Reverse osmosis plants are becoming common in the coastal cities.
a) What do you think is its importance?
b) What values do you associate with your reasons?
27. In earlier days food items and products like cooking oil, sugar and biscuits were packed in tin containers. These containers were then used by housewives for storing grains and other kitchen items. Now exports / imports in tin containers are strictly prohibited; in spite of this we still seem to permit the tin containers for soft drinks!
a) What do you think is the reason for the prohibition?
b) Should we continue to use soft drink cans?
c) What values are involved in this paragraph of information?
28. Two iron plates, with dents were allotted to two students for plating and study of prevention of rusting. The first student selected tin for coating his plate, while the second chose zinc for the same purpose.
a) Who do you think made the right choice, and why?
b) Mention one value associated with the study of corrosion.
29. Automobiles fitted with catalytic convertors are more expensive and they become out of the reach for middle class population. The catalytic convertors help converting the unburnt particles in the fuel and CO into less harmful CO2 and let them out of exhausts.
a) Do you think it is necessary to fit in these catalytic convertors in automobiles? Justify.
b) Whar are the values involved in your decision?
30. Leather tanning is an important industry for our country’s economy. Effluents from the leather industries contain a lot of toxic compounds and they are let into the water bodies causing pollution and foul smell. Local people in that area are most affected and this has lead to closing down of many tanneries.
a) What are the changes that occur during tanning of skin?
b) Which biomolecules make animal skin?
c) What are the values associated in closing of tanneries?
31. Few boys were playing next to a paddy field in a village, noticed a farmer bleeding profusely due to a deep cut on his leg because of wrong handling of the pick axe. One of the boys ran into the field and got wet clay and applied on the cut. The man was then taken to the nearby hospital.
a) The other boys asked the boy who applied the clay, why he did so?
b) what do you think was his answer?
c) What value did you learn from the incident?
32. Water for drinking purpose can be sterilized using ozone gas or chlorine gas.
a) Which is preferable over the other, why?
b) What are the values taken into consideration in sterilizing water?
33. Most of the villagers of a coastal village were found having swollen neck (affected by goiter.) When examined, they were using local salt, prepared by natural evaporation of back waters of sea.
a) As a student of chemistry how will you address this problem?
b) What value do you associate with it?
34. Due to scarcity of water, the residents of a colony decided to reuse their well which was not used for past six months. The secretary decided to clean the well by adding small amount of potassium permanganate in the well, and then loaded the well water with Aluminium alum crystal.
a) Why do you think he added potassium permanganate in the well?
b) How does loading with alum help?
c) What are the values involved in this process?
35. In an electroplating shop that the students visited as part of their industrial visit they observed that the plating of silver on cutlery is dull, even though the concentration AgNO3(aq) is good. The students suggested them to use K[Ag(CN)2](aq) instead of AgNO3(aq). They could get good difference in the quality of the plating after changing the electrolyte.
a) Explain the reasons for obtaining bright and uniform plating.
b) What are the values attached with the students’ approach?
36. Ram and Salim decided to do their chemistry project together, and both were fond of Organic chemistry; they chose an interesting topic which involves the usage of some organic solvents as well as aerosol propellants. When they approached their teacher to get her consent on the topic, she refused, and told them to choose some other topic but not this.
a) Why did the teacher denied ?
b) What does this tell us about the teacher?
37. Abhishek decided to visit his village during summer holidays with his friends where his grandparents were staying. One day, while going for a walk they happened to hear the farmers discussing about how the pests have destroyed their crops, which caused a great loss, inspite of spraying pesticides. One of them suggested that they use DDT to have better control on pests and others agreed. On hearing this Abhishek and his friends were worried and they convinced the farmers against the usage of DDT.
a) Write expansion of DDT, and its structure.
b) Why were the friends worried about use of DDT?
c) What are the values that can be leant from the action of friends?
38. Ramu had drunk from a local wine shop. He complained of blurred vision, started losing his eyesight slowly and died in a couple of days.
a) What could be the reason for his death?
b) Give IUPAC name of main component of wine.
c) What values can be derived from the sad incident?
39. Ram’s mother always followed very traditional way of cooking using earthen wares, copper utensil. Her daughter replaced all the kitchen utensils with Teflon coated ones.
a) In your opinion who is correct in the present life situation?
b) What is the monomer of Teflon? What is its structure?
c) What are the values involved?
40. The Government order directs the shop keepers to charge their customers bags, to take the items that they purchase.
a) Name the different types of polythene available.
b) Why does the Government impose such an order?
c) What are the values involved in the Government order?
41. Shyam’s grandma complained of irritation and pain in her stomach. He called the family doctor, but got an appointment only in the evening. Meanwhile he gave her ranitidine tablet for an immediate relief.
a) In your opinion, is Shyam’s action justifiable?
b) What type of drug is ‘Ranitidine?’
c) What are the values associated with Shyam’s action?
42.Neeta’s grandmother diabetic patient, wished to have homemade sweets. Neeta went to a nearby super market to buy artificial sweeteners to make sweets. She noted two brands of sweeteners, one containing aspartame and the other containing sucrolose. Neeta chose the brand having sucrolose
a) Why did Neeta choose this brand?
b) Is ‘Aspartame’ a disaccharide? How is ‘Sucrolose’ different from ‘Sucrose?’
c) What are the values that Neeta brings out through her action.
43. According to a report from Harvard’s school of Public Health published in ‘Change= the magazine of Higher Learning” in 1996, a study conducted by Henry Weshler& Associates found that as the number of drinks (alcohol) per week increased, academic performance decreased.
a) How is ethyl alcohol made unfit for consumption?
b) How is Ethyl alcohol manufactured from molasses?
c) What values can be derived from this information?
44. Ram was travelling in a car with his driver. They were stopped by a policeman and the driver was asked to take the breath analyzer test for alcohol. He was asked to blow air into the device which contained a pink solution. The solution faded in colour.
a) What is the pink coloured solution? Why does it fade?
b) Why are such tests conducted on drivers?
c) What are the values involved in the action of policeman?
45. Brazil is the world's second largest producer of ethanol fuel and the world's largest exporter. Together, Brazil and the United States lead the industrial production of ethanol fuel. Brazil’s sugarcane ethanol is "the most successful alternative fuel to date." There are no longer any light vehicles in Brazil running on pure gasoline. Since 1976 the government made it mandatory to blend anhydrous ethanol with gasoline. Since July 1, 2007 the mandatory blend is 25% of anhydrous ethanol and 75% gasoline or E25 blend.
a) Why do you think Brazil has made it mandatory to blend gasoline with ethanol?
b) What could be the reason for Brazil being the second largest producer of ethanol?
c) What are the values involved in use of ethanol substitute for gasoline?
46. A group of students were given to study the properties of aldehydes and ketones in the lab. They recorded a few observation of their physical properties.
a) Why are aldehydes more reactive and more soluble than ketones?
b) What values can be learnt from behavior of aldehydes?
47. A group of students were allotted a project to determine the molar mass of Benzoic acid in a non-polar solvent (benzene) by Rast Method. But the students observed the value of the molar mass of benzoic acid was double the formula wt., this led them to confusion.
a) Why was the molar mass double the theoretical mass?
b) What type of property is useful in determination of molar mass of a non-volatile substance?
c) What values can be derived from the behaviour of Benzoic acid.
48. Ramesh went to Cinema theatre driving his car under foggy weather and met with an accident due to unbalanced driving with hindered beam of light.
a) Define Tyndall effect.
b) Which type of colloid is the fog?
c) Mention the value associated with the above situation.
49. Mohan and Rahul are good friends, they went to attend a marriage function neatly dressed. There unfortunately a boy splashed some eatable on their shirts which left oil stain, which Mohan washed with plain water but Rahul washed with soap water.
a) What is CMC?
b) Why Rahul’s shirt looks neat but Mohan’s shirt still carried oil stain?
c) Write the value associated with above incident.
50. Ram was playing football. He fell down and had a bad cut in his knee and he startedbleeding. The Chemistry lab was situated very close to the football court. Shyam immediately brought a bottle of ferric chloride while Sundar brought a bottle of potassium chloride. After debating for a few seconds, a spatula of ferric chloride was applied to the wound and the
bleeding was arrested.
Contextual question: Why is ferric chloride preferred over potassium chloride in case of a cut leading to bleeding?
Value: What value does the behaviour of Ram’s friends reflect?
51. A factory was situated very close to the Residential area where Rita lived . The factory worked round the clock and the smoke coming out of the chimneys was causing a lot of health problems to people living in the area. Rita and few others
decided to meet the top officials of the factory and give them the idea of installing the Cottrell’s Smoke Precipitator.
Contextual question: What is the purpose of having the Cottrell’s Precipitator installed ?
Value: What value do you attribute to Rita’s concern?
52. Reena was admiring the clear blue sky and was talking to her friend about the beautiful clear sky in the evening as they were taking a walk in the beach. She looked at the sky and exclaimed –“ look at the sky. It looks red now”. Reena
asked her friend Rita if she could explain why the clear blue sky in the morning looked red at dusk.
Contextual question: Explain why the sky appears blue in the morning and the sun looks red at the time of setting?
Value: What value does Reena’s explanation reflect?
53. Shakthi’s village was facing a lot of problem with the sewage disposal.The environment was became unhealthy and unhygenic .Shakthi and her friends decided to talk to the village chief and find a solution for this problem. She came out with
the idea of allowing the sewage water to pass through the tunnel fitted with metallic electrode maintained at high potential difference. This method will not only provide water from irrigation but also manure for the fields.
Contextual question: Why did Shakthi insist on the sewage water being passed through electrode fitted tunnels?
Value: What value does the attitude of Shakthi and her friends relect?
54. Babu was suffering from stomach disorder . The doctor prescribed Milk of Magnesia as remedy and it would be effective since it is an emulsion. Babu went home and asked his mother what an emulsion was and why emulsions are more effective?
Contextual Question: What is an emulsion ? Why are medicines in emulsion form more effective?
Value: What value does Babu’s question reflect?
55. Asha gives an induction stove to her friend Nish as a gift. Nisha immediately places a a curved base copper cooker to cook but it failed to work. Thinking that the piece is defective she gets annoyed and wants to call up the service center. Her son beside her reads the catalogue and instructs her to use Al and steam flat based cooker . a. What is the chemistry behind it and what are the values derived from this incident?
What are the Values associated with the above ?
56. Two group or students are provided with 50 lemons each and a small circular plate. They are asked to arrange them in an orderly manner in 5 minutes. One team successfully arranges the lemons while other team was not able to complete the
task. What is the mode of packing had the team adopted ? What are the Values offered?
57.Bunty a chemist, during the construction of his house adviced the civil engineer to leave a gap in wooden fittings of glass window panes to avoid cracks. What is the chemistry involved in advising the civil engineer? What values can be imbibed from this?
58. Ajay had managed to purchase large quantities of iron scrape from the corporation, with an intention of starting a factory for making screws and bolts. But his friend suggested an alternative idea of using this in electromagnets. What would you think was his decision and what were the values inculcated?
59.Sonia was punctual to school while Aditi was not punctual. The teacher wanted to analyse why Aditi was late to school while Sonia was punctual while both of them came from the same place. Aditi expressed that her mother took longer time to
provide breakfast and lunch so she was late to school. The teacher concluded that the methodology og cooking was different. Aditi’s mother used conventionalmethods of cooking while Sonia’s mother used pressure cooker. Why is cooking with pressure cooker more preferred? What values are included from the above happening?
60. Asha and Meena bought meat from butcher . She salted the meat for preservation while Meera refrigerated meat. Which meat can last longer?
61.Rahul sees his grandfather’s swollen leg and advices him to take less salt in his food and ensures that the food cooked at home contains less salt. Why did the child insist to reduce the intake of salt and what are the values that can be developed?
62. Students went to Kashmir for excursion in winter and saw the roads covered with snow. It was being cleared by shoveling it. One group of students advised sprinkling of salt and another group advised use of calcium chloride. The first suggestion was taken to clear the snow. Why was the first suggestion adopted? What are the values derived from he above incident?
63.At a site, low grade copper ores are available and zinc and iron scrapes are also available. As a student of chemistry , which of the two scrapes will you suggest for reducing the leached copper and why? What are the values associated with the above decision?
64 .Shyam wanted to take a good picture of his grandmother but Shyam had only an ordinary camera. His friend Ram suggested him to make use of Aluminium powder. How is Al powder helpful? What value did Ram give to Shyam?
65. Wrought iron is preferred over cast iron for making anchors and railway carriage couplings. Why? What are the values associated with above?
66. Suresh who runs a school canteen decided to replace the Al containers used for storing water by steel container even though steel is costlier. Why? What is the value associated with this decision?
67. Vishal and Anurag were arguing about the ban on supersonic jets. Vishal was against the use of it. Anurag supported it as it is fast and saves time. Why do you think Vishal is right and what is the value you gain?
68. Chlorine gas is the very useful gas. At the same time it can be used for the manufacture of certain poisonous gases. Name two useful and poisonous gases manufactured from chlorine? The teacher while teaching made the student aware of both merits and de – merits of chemicals. What value based education she tried to impart?
69. While taking the class on noble gases the teacher related the story about how Neil Barlett tried many experiments before he manufactured Xe compounds. Which compound was this? What inspiration do you get from him?
70. While analyzing a salt Rina reported acid radical as nitrate as it gave brown gas with conc. Sulphuric acid. But the teacher disagreed. Her friend Rupa helped her and suggested another test. What other radical it could be? Suggest the test for the radical. What moral value do you take from Rupa’s action?
71. Mohan while diluting concentrated acid added water to it. This caused splashes and he suffered minor burns on his hands. Dinesh came to his help, took him to the medical room for first aid and also explained the right way to dilute sulphuric acid Explain why Mohan’s method of dilution caused splashes? What moral value is highlighted by Dinesh action?
72. The metals used in application such as mobile phones, nuclear reactors, batteries etc are so rare that these critical metals will be unavailable for use in modern technology.
*What measures would you suggest to overcome this situation?
*What value would be promoted by the measure you adopt?
* Name any two rare transition metals.
73. A Poster suggests the following life style on the part of families/individuals.
a. Use organic food products.
b. Use KMnO4 for bleaching purpose instead of using chlorine based bleaching agents.
c. Use alloy steel to furnish home needs than wood.
d. Use bicycle for travelling short distances than petrol/diesel vehicles.
I. Which environmental values are promoted through these life style.
II. Suggest one additional life style action for promotion of green chemistry.
III. Give reason for the bleaching action of KMnO4
74. For automotive catalytic converters, transition metals like Pt, Pd, Rd, Fe, Cr etc used in industry are expensive while eramic cores are inexpensive.
i. Which property of transition metal makes them useful as catalyst?
ii. Which value is promoted through the use of catalytic converters in industry?
As a student of chemistry would you suggest the use of expensive & rare metals like Pt, Pd & Rh give reasons.
75. Sam and his neighbor Ram have got their home fenced with iron rods. Sam saw the next day that Ram was painting the iron fence. Ram suggested Sam to do the same to increase the longevity of iron rods by preventing corrosion. Sam argues that its waste of time & the iron rods are quite strong. After reading the above passage, answer the following question.
i. Whose opinion is correct according to you? What values are promoted here?
ii. Why do iron objects found near the sea get corroded faster?
iii. Are there any other ways to prevent corrosion other than painting.
76. An element X has low melting point and high density, It is used in thermometers and barometers and its oxide is used in batteries.
i. Name the element X.
ii. Why is the use of the element X in skin lightening creams not recommended?
iii. Should we advocate the use of metal free cosmetics ? which value is reflected in this approach?
77. A junior scientist reports the use of silver amalgam to control tooth decay can result in getting a deadly disease and recommends the use of biocompatible resins.
i. Why the use of silver amalgam in dentistry is banned in many countries?
ii. Which value is reflected in this ban?
iii. What is the advantage of biocompatible products?
78. An NGO decided to supply KMnO4 in villages in monsoon to be added to water bodies. Why? What is the value behind this decision?