Question

.The density of a gas A is twice that of B. Molecular mass of A is half of molecular mass of

B. The ratio of partial pressure of A and B is.

(a) 1/4 (b) 1/2 (c) 4/1 (d) 2/1​

Answer 1

Answer:

The partial pressure ratio of A and B is 4:1.

Explanation:

Density of gas A = 2d

Density of gas B = d

Molar mass of gas A ,m= \frac{1}{2}M

2

1

M

Molar mass of gas B ,m'= M

Density=\frac{P\times M}{R\times T}Density=

R×T

P×M

Partial pressure of gas A = p_Ap

A

2d=\frac{p_A\times m}{R\times T}2d=

R×T

p

A

×m

..(1)

Partial pressure of gas B = p_Bp

B

d=\frac{p_B\times m'}{RT}d=

RT

p

B

×m

′

..(2)

Dividing (1) and (2):

\frac{2d}{d}=\frac{\frac{p_A\times m}{R\times T}}{\frac{p_B\times m'}{RT}}

d

2d

=

RT

p

B

×m

′

R×T

p

A

×m

2=\frac{p_A\times \frac{1}{2}M}{p_B\times M}2=

p

B

×M

p

A

×

2

1

M

\frac{p_A}{p_B}=\frac{4}{1}

p

B

p

A

=

1

4

The partial pressure ratio of A and B is 4:1.