The density of a gas at `27^(@)C` and `1 atm` is `d`. Pressure remaining constant, at which of the following temperture will its density become `0.75 d`?

Options

A. `20^@C`
B. `30^@C`
C. 400K
D. 300K

Answer

C

Explanation

At constant pressure:
`V prop nT prop m/M T`
`V_1/V_2 = (m_1T_1)/(m_2T_2) therefore T_1/T_2 = V_1/m_1 xx m_2/v_2 = d_2/d_1`
`rArr (300K)/(T_2) = (0.75d)/(d)`
`T_2 = (300)/(0.75) = 400K`