Question 8
Distinguish between the vapour density and the normal density of a gas.
[Hints: Normal density of a gas is the weight of 1 litre of gas at STP, it has unit gram/litre at STP, depending on temperature and pressure. Vapour density is a ratio, has no unit, and does not depend on temperature and pressure]
Answer
Vapour density and normal density are two different concepts related to the properties of gases.
- Vapour Density:
Vapour density is the density of a gas or vapour in relation to the density of a reference gas, which is usually dry air or hydrogen, at the same temperature and pressure.
- Normal Density:
Normal density is the density of a gas at standard temperature and pressure (STP), which is defined as 0°C and 1 atmosphere (atm) of pressure.
