please solve value based question fastly .
Answers
1. Manu went with his father to a Shopkeeper who showed them two types of batteries, one with lead plates and the other with cadmium plates. The battery with cadmium plates was more expensive than the lead battery. Manu’s father wanted to purchase lead battery as it was cheaper.
a. As a student of chemistry, why would you suggest to Manu’s father to buy the expensive cadmium plate battery. Give two reasons. (2)
b. What are the values associated with the above decision?
Ans:
a. Cadmium plate battery though expensive is not as strong a pollutant as lead. Lead salts being insoluble in water if ingested into our system cannot be excreted out. Whereas Cd and Ni salts are water soluble, therefore get excreted and hence do not get biomagnified in
the body.
b. Keeping the environment safe from pollution due to lead.
4. After entering a closed coal mine area, Ravi found difficulty in breathing, also felt nausea.
a. What could be the reason for this? (1)
b. How could Ravi estimate the level of the pollutant? (1)
c. As a citizen of the country what should be his course of action
further? (1)
Ans:
a. In coal mines due to lack of oxygen a small percentage of carbon monoxide is formed. This carbon monoxide being poisonous gives the symptoms.
b. Ravi could estimate the level of CO using I2O5.
c. Ravi should inform the concerned authority about the excess
of CO in the coal mine.
5. Sudanshu made a model of the unit cell of diamond. It resembled the unit cell of ZnS. If the unit cell of ZnS has 4 units of ZnS per unit cell. It has the same packing efficiency as ZnS. But diamond is the hardest known substance.
a. What is the number of atoms of carbon per unit cell of diamond?
(1)
b. Why? (1)
c. What is the value that Sudanshu can derive from these facts?(1)
Ans:
a) The number of atoms of Carbon per unit cell is 8 in diamond.
b) The C—C bond is very strong in diamond (due to small size of Carbon) unlike the Zn—S bond in ZnS.
c) Though from the same background ie with the same structure the property can be different, thus, with a little effort, we can do same things differently and bring about major changes.
6. Kartick went to a sugar producing factory. He noticed an alcohol producing unit associated with it. Generally alcohol is prepared industrially in places where sugar is extracted from sugarcane.
a. As a student of chemistry can you tell Why? (2)
b. What is the value derived from this fact? (1)
Ans:
a. The molasses that are bi-products of sugar industry can be used in making alcohol.
b. Recycling of industrial waste keeps the environment clean.
7. Large amount of electricity is obtained in our country from burning of coal. The carbon in coal is lost as carbon dioxide, and water as water vapour. The substances left behind are minerals. These are known as fly ash. Fly ash is a major
environmental hazard. Faseeh did a project on how to use this fly ash in building
roads and in making roofing tiles. He was appreciated by the judges. What was
the value for which he was appreciated?
Ans: Recycling of industrial waste keeps the environment clean. (3)
8. Ashraf is 50 years old and has diabetes. He uses saccharine as sweetening agent in tea and coffee and sugar free in sweets. Lakshmi too is diabetic. She controls her sugar level in diet by using less sugar and by exercising.
a. Who is able to handle diabetes more efficiently and why? (1)
b. What value do you derive from this? (1)
c. What are the harmful effects of artificial sweeteners? (1)
Ans:
a. Lakshmi is able to handle diabetes better, because exercises activate the pancreases to produce insulin. Exercise keeps one fit and fine.
b. It is necessary to lead a disciplined life.
c. Researches have shown that the artificial sweeteners have harmful effect on the body because they are not excreted easily.
9. Almelu did not like the costlier brand of dish washer because she was not satisfied by using less quantity of the dishwasher, so she bought the cheaper brand of dish washer and used large amounts of it.
a. As a student of chemistry what would you advise Almelu to use? (1)
b. Why? Explain. (1)
c. What value did you impart to Almelu? (1)
Ans:
a. I would advise Almelu to use smaller quantities of the costlier detergent.
b. Almelo was pouring detergents into the drain. These detergents are not biodegradable. Branched detergents are highly nondegradable because the microbes cannot attack it. Straight chain detergents are being prepared these days to reduce the pollution problem. The costlier detergent contains straight chain hydrocarbon.
c. The value imparted was to use environmentally friendly substances.