Question

calculate the vapour pressure of a solution containing 9g of glucose in 162g of water at 293k. the vapour pressure of water at 293k is 17.535mmHg​

Answer 1

Answer:

The vapor pressure of the solution will be 17.45 mm of Hg

Explanation :

Given,

weight of water = 162 g

=> number of moles of water, n₁ = 162/18 = 19

weight of glucose = 9 gm

=> number of moles of glucose, n₂ = 9/180 = 1/20

we know that vapor pressure of pure water at 293 k, P⁰ = 17.5 mm of Hg

From Raoult's law,

(P⁰-P)/P⁰ = n₂/n₁

=> 1 - P/P⁰ = 1/(20x19)

=> P/P⁰ = 379/380 = 0.99

=> P = 17.5 x 0.99 = 17.45 mm of Hg

Hence the vapor pressure of the solution will be 17.45 mm of Hg