Question

Vapour pressure of water at 293 Kelvin is 17.536 mmHg. Calculate the vapour pressure of an aqueous solution when 20 g of glucose is dissolved in 500 g of water.

a. 17.236 mmHg
b. 17.936 mmHg
c. 18.236 mmHg
d. 18.536 mmHg

Answer 1

To calculate the vapor pressure of an aqueous solution, we can use Raoult's Law.

Step-by-step explanation:

To calculate the vapor pressure of an aqueous solution, we can use Raoult’s Law. Raoult’s Law states that the vapor pressure of a solution is equal to the mole fraction of the solvent multiplied by the vapor pressure of the pure solvent.

First, let's calculate the mole fraction of water:

Mole fraction of water = moles of water / moles of water + moles of glucose = (mass of water / molar mass of water) / (mass of water / molar mass of water + mass of glucose / molar mass of glucose)

Now, we can use Raoult's Law:

Vapor pressure of solution = mole fraction of water * vapor pressure of water