What is the mole fraction of ethanol in a mixture of 9 g water and 46 g ethanol?
Answer and explanation
Correct answer: about 0.667
The mole fraction of a component is its amount in moles divided by the total moles of all components. Water contributes 9 ÷ 18 = 0.5 mol, and ethanol contributes 46 ÷ 46 = 1.0 mol. Total moles are 1.5, so the ethanol mole fraction is 1.0 ÷ 1.5 = 0.6667, approximately 0.667. Thus A is correct; 0.333 is the water mole fraction.
Frequently asked questions
What is the correct answer to this question?
about 0.667
Why is this the correct answer?
The mole fraction of a component is its amount in moles divided by the total moles of all components. Water contributes 9 ÷ 18 = 0.5 mol, and ethanol contributes 46 ÷ 46 = 1.0 mol. Total moles are 1.5, so the ethanol mole fraction is 1.0 ÷ 1.5 = 0.6667, approximately 0.667. Thus A is correct; 0.333 is the water mole fraction.
Which subject and chapter does this question cover?
This is a Class 11 Chemistry question. Chapter: Chapter 01: Solutions.
