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

In which of the following electrolytic cells [P, Q, R or S] will silver plating be done on the spoon?

1. P
2. Q
3. R
4. S

The basicity of acetic acid is:

1. 1
2. 2
3. 3
4. 4