Question

What is density of air at normal temperature pressure condition?

(a) 998.2 kg/m^3

(b) 1.290 kg/m^3

(c) 1290 kg/m^3

(d) 9.982 kg/m^3

I had been asked this question in an internship interview.

My question is taken from Numerical Problems Based on Combustion and Fuel Gas Analysis topic in section Fuels and Combustion of Engineering Chemistry II

Answer 1

The correct option is (b) 1.290 kg/m^3

Easiest explanation: The density of air at normal temperature pressure is 1.290 kg/m^3 or 1.290 gm/cm^3. The density of water at normal temperature at N.T.P is 998.2 kg/m^3.