The density of gas A is twice that B. At the same temperature the molecular weight of gas B is twice that of A. The ratio of pressure of gas A and B will be

Question

The density of gas A is twice that B. At the same temperature the molecular weight of gas B is twice that of A. The ratio of pressure of gas A and B will be (A) 1:6 (B) 1:1 (C) 4:1 (D) 1:4

Tardigrade Admin · Accepted Answer

dA=2dB;2MA=MB; As PM=dRT So (PA/PB)× (MA/MB)=(dA/dB)× (R T/R T) (PA/PB)× (1/2)=2 (PA/PB)=(4/1)

Q. The density of gas A is twice that B. At the same temperature the molecular weight of gas B is twice that of A. The ratio of pressure of gas A and B will be

1:6

1:1

4:1

1:4

$d_{A} = 2 d_{B}; 2 M_{A} = M_{B};$

As $PM = d RT$

So $\frac{P _{A}}{P _{B}} \times \frac{M _{A}}{M _{B}} = \frac{d _{A}}{d _{B}} \times \frac{RT}{RT}$

$\frac{P _{A}}{P _{B}} \times \frac{1}{2} = 2$

$\frac{P _{A}}{P _{B}} = \frac{4}{1}$

Q. The density of gas A is twice that B. At the same temperature the molecular weight of gas B is twice that of A. The ratio of pressure of gas A and B will be

1:6

1:1

4:1

1:4

dA​=2dB​;2MA​=MB​; As PM=dRT So PB​PA​​×MB​MA​​=dB​dA​​×RTRT​ PB​PA​​×21​=2 PB​PA​​=14​

$d_{A} = 2 d_{B}; 2 M_{A} = M_{B};$

As $PM = d RT$

So $\frac{P _{A}}{P _{B}} \times \frac{M _{A}}{M _{B}} = \frac{d _{A}}{d _{B}} \times \frac{RT}{RT}$

$\frac{P _{A}}{P _{B}} \times \frac{1}{2} = 2$

$\frac{P _{A}}{P _{B}} = \frac{4}{1}$