PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions for Chemistry

Out of C and CO, which is a better reducing agent at the lower temperature range in the blast furnace to extract iron from the oxide ore?

What use of drugs is used in sleeping pills?

What is the role of cryolite in the extraction of aluminium?

What is the role of limestone in the extraction of iron from its oxides?

Due to hectic and busy schedule, Mr Angad made his life full of tensions and anxiety. He started taking sleeping pills to overcome the depression without consulting the doctor. Mr Deepak, a close friend of Mr. Angad advised him to stop taking sleeping pills and suggested to change his life lifestyle by doing yoga, meditation and some physical exercise. Mr. Angad followed his friend’s advice and after few days he started feeling better.

After reading the above passage, answer the following

(i) What are the values (at least two) displayed by Mr. Deepak?

(ii) Why is it not advisable to take sleeping pills without consulting doctor?

(iii) What are tranquilisers? Give two examples.

What is the role of CO in the extraction of Iron?

In the extraction of Al, impure Al₂O₃ is dissolved in conc. NaOH to form sodium aluminate and leaving impurities behind. What is the name of this process?

What is the role of coke in the extraction of iron from its oxides?

Indicate the principle behind the method used for the refining of zinc.

What is the role of silica in the extraction of copper?

Which form of the iron is the purest form of commercial iron?

Describe the roles of the following: SiO₂ in the extraction of copper from copper matte

Name the method used for refining of copper metal.

Classify the following solids in different categories based on the nature of intermolecular forces operating in them:

Potassium sulphate, tin, benzene, urea, ammonia, water, zinc sulphide, graphite, rubidium, argon, silicon carbide.

Classify each of the following solids as ionic, metallic, molecular, network (covalent) or amorphous.

1. Tetra phosphorus decoxide (P₄O₁₀)
2. Ammonium phosphate (NH₄)₃PO₄
3. SiC
4. I₂
5. P₄
6. Plastic
7. Graphite
8. Brass
9. Rb
10. LiBr
11. Si

Define the term solution.

Which of the ores mentioned can be concentrated by magnetic separation method?

Differentiate between “minerals” and “ores”.

Write the formula for the following coordination compound:

Iron (III) hexacyanoferrate (II)

Sleeping pills are recommended by doctors to the patients suffering from sleeplessness but it is not advisable to take its doses without consultation with the doctor, Why?