The vapour pressure of pure liquid textA is text10 texttorr and at the same temperature when text9 textg of textB solid dissolved in text20 textg of textA, its Vapour pressure is reduced to text5 texttorr text. If the molecular mass of textA is text200 textamu, then the molecular mass of textB is

Question

The vapour pressure of pure liquid textA is text10 texttorr and at the same temperature when text9 textg of textB solid dissolved in text20 textg of textA, its Vapour pressure is reduced to text5 texttorr text. If the molecular mass of textA is text200 textamu, then the molecular mass of textB is (A) 100 amu (B) 90 amu (C) 75 amu (D) 120 amu

Tardigrade Admin · Accepted Answer

(P0 - Ps/Ps)=(n/N) (10 - 5/5)=(9 × 200/M × 20) textM text= text90 textamu

Q. The vapour pressure of pure liquid $A$ is $10 torr$ and at the same temperature when $9 g$ of $B$ solid dissolved in $20 g$ of $A,$ its Vapour pressure is reduced to $5 torr .$ If the molecular mass of $A$ is $200 amu,$ then the molecular mass of $B$ is

100 amu

90 amu

75 amu

120 amu

$\frac{P ^{0} - P _{s}}{P _{s}} = \frac{n}{N}$

$\frac{10 - 5}{5} = \frac{9 \times 200}{M \times 20}$

$M = 90 amu$

Q. The vapour pressure of pure liquid A is 10torr and at the same temperature when 9g of B solid dissolved in 20g of A, its Vapour pressure is reduced to 5torr. If the molecular mass of A is 200amu, then the molecular mass of B is