Twice the vapour density gives:

1. actual vapour density

2. relative vapour density

3. molecular mass

4. molar volume

The empirical formula of the compound is CH₂O, the possible molecular formula can be:

1. C₃H₆O₃

2. C₂H₄O

3. C₄H₃O₂

4. C₄H₆O₂

If the empirical mass of the formula PQ₂ is 10 and the relative molecular mass is 30, then the molecular formula will be:

1. PQ₂

2. P₃Q₂

3. P₆Q₃

4. P₃Q₆

The ratio between the number of molecules in 2 g of hydrogen and 32 g of oxygen is:
[Atomic mass: H=1, o=16]

1. 1:2

2. 1:0.01

3. 1:1

4. 0.01:1