Water has a vapor pressure of 23.75 at 250c what is the vapor pressure of a solution sucrose if its mole fraction is 0.25?
Correct answer: B. 17.8 torr
- A. 15.2 torr
- B. 17.8 torr
- C. 23.8 torr
- D. 29.7 torr
Explanation
Mole fraction of the solute = xs = 0.25Pressure of the solvent = PH2O = 23.76 torrFirst, we solve for the mole fraction of the solvent.x(H2O) = 1 - 0.25 = 0.75Now, we can solve for the pressure of the solution:P(sol) = (xH2O)(PH2O)= (0.75) (23.76 torr)P(sol) = 17.82 torrTherefore, the vapor pressure of the solution is 17.82 torr.
This question appeared on the ETEA MDCAT 2010 paper, which you can sit online with every answer explained.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Colligative Properties
Colligative properties depend on the number of dissolved particles rather than their chemical identity. The topic covers relative lowering of vapour pressure, elevation of boiling point, depression of freezing point and osmotic pressure, including electrolyte dissociation, the van’t Hoff factor and molar-mass calculations.
Practise Solutions and Colloids
119 free Solutions and Colloids MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Chemistry questions like this
Chemistry is on 14 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Colligative Properties questions
Lowering in vapour pressure is the highest for:
The vapor pressure lines for pure as well as solutionsof different concentrations are shown. Which line represents pure water?
Osmotic pressure of a solution is _ property.
Pure water freezes at 0 oC and boils at 100 oC at standard conditions. Calcium chloride was added to pure water. What do you expect about its freezing point and boiling point?
The osmotic pressure of dilute solution is given by the formula:
The osmotic pressure of dilute solution is given below by relationship: