Question

The vapour density of carbon dioxide [C=12, O=16] is:
A.32
B.16
C.44
D.22

Answer 1

Hint: Carbon dioxide is a colorless gas and its density is higher than that of dry air. It is present in the air but in a very minute quantity. It is considered as a greenhouse gas.
Formula used:
${\text{Vapour density = }}\dfrac{{{\text{Molecular weight}}}}{{\text{2}}}$

Complete step by step answer:
Carbon dioxide gas contains carbon atoms forming a double bond with two oxygen atoms. Carbon dioxide is used in the food industry, oil industry and chemical industry. It has a variety of uses, one of them is that it is being used in the carbonated drinks.
Carbon dioxide contains one carbon atom and two oxygen atoms. The atomic weight of carbon is 12 and that of oxygen is 16. Hence the total molecular weight of carbon dioxide is 12+16+16 which is equal to 44.
Vapour density of any gas is the density of that gas with respect to hydrogen. The vapour density of any gas can also be written as the molecular weight of that gas divided by the molecular weight of hydrogen gas.
The molecular weight of hydrogen gas is 2. Hence the vapour density of any gas can be given as the molecular weight of that gas divided by 2.
${\text{Vapour density = }}\dfrac{{{\text{Molecular weight}}}}{{\text{2}}}$
In this question, the vapour density of the carbon dioxide is equal to the molecular weight of carbon dioxide divided by 2.
Hence the vapour density of the carbon dioxide is 44 divided by 2 which is equal to 22.

Therefore, the correct answer to the question is 22, that is, option D.

Note:
Carbon dioxide is essential for the process of photosynthesis. Important refrigerants used in chemistry are solid and liquid carbon dioxide. Carbon dioxide is also present in the ocean in the form of carbonic acid.