What is the mole fraction of ethanol in a mixture of 46 g ethanol and 54 g water? Molar masses are 46 and 18 g/mol respectively.
Answer and explanation
Correct answer: 0.25
The governing concept is mole fraction: the mole fraction of a component equals its amount in moles divided by the total moles of all components. Ethanol contributes 46/46 = 1 mol, while water contributes 54/18 = 3 mol. Therefore, total moles = 4 and x_ethanol = 1/4 = 0.25. Option A is correct. The other values can result from using masses directly or confusing the ethanol fraction with another ratio.
Frequently asked questions
What is the correct answer to this question?
0.25
Why is this the correct answer?
The governing concept is mole fraction: the mole fraction of a component equals its amount in moles divided by the total moles of all components. Ethanol contributes 46/46 = 1 mol, while water contributes 54/18 = 3 mol. Therefore, total moles = 4 and x_ethanol = 1/4 = 0.25. Option A is correct. The other values can result from using masses directly or confusing the ethanol fraction with another ratio.
Which subject and chapter does this question cover?
This is a Class 11 Chemistry question. Chapter: Chapter 01: Solutions.
