A compound P is heated in a test tube with sodium hydroxide solution. A red litmus paper held at the mouth of the test tube turns blue. Which of the following could compound P be?

1. zinc sulphate
2. copper sulphate
3. ferrous sulphate
4. ammonium sulphate

The atomic masses of sulphur (S), oxygen (O), and helium (He) are approximately 32, 16, and 4 respectively.
Which of the following statements regarding the number of atoms in 32 g of sulphur, 16 g of oxygen, and 4 g of helium is correct?

P. 16 g of oxygen contains four times the number of atoms as 4 g of helium.

Q. 16 g of oxygen contains half the number of atoms as 32 g of sulphur.

1. only P
2. only Q
3. both P and Q
4. neither P nor Q

Ammonia gas is passed through quicklime and then collected in a jar. Red and blue litmus papers are placed in the jar. W, X, Y and Z are the four observations. Which of the above observations correctly shows the reaction of the litmus papers to ammonia?

1. W
2. X
3. Y
4. Z

Glucose reacts with concentrated sulphuric acid to give a very pure form of carbon called sugar charcoal.

The reaction taking place is:

1. oxidation
2. combustion
3. dehydration
4. combination