Question

Temperature of an ideal gas is T K and average kinetic energy is E = 2.07 x 10^-23  T Joule/molecule. Number of molecules in 1 litre gas at S.T.P. will be

(a) 2.68 x 10²² 

(b) 2.68 x 10²⁵

(c) 2.68 x 10²⁸ 

(d) 1.68 x 10²²

Answer 1

Correct Option (a) 2.68 x 10²² 

Explanation: 

As we know that at S.T.P. 22.4 litre of gas contains 6.023 x 10²³ molecules

1 litre of gas contain  6.023 x 10²³/22.4 = 2.68 x 10²² molecules.