Question

The number of air molecules in a (5m x 5m x 4m) room at standard temperature and pressure is of the order of

(a) 6 x 10²³

(b) 3 x 10²⁴

(c) 3 x 10²⁷

(d) 6 x 10³⁰

Answer 1

Answer is : (c) 3 x 10²⁷

From ideal gas equation,

pV = nRT ⇒ pV = Nk_BT or N \(=\frac{pV}{k_BT}\)

Substituting given values, we get