36 g glucose is dissolved in water to make 400 mL solution. Molar mass of glucose is 180 g per mole. What is the molarity?
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Answer and explanation
Correct answer: 0.5 mole per litre
Molarity is the number of moles of solute per litre of final solution. The glucose amount is n = 36 g ÷ 180 g mol−1 = 0.20 mol. Convert the final volume: 400 mL = 0.400 L. Hence M = 0.20 ÷ 0.400 = 0.50 mol L−1, so option A is correct. Using the water volume instead of final solution volume would be incorrect.
Frequently asked questions
What is the correct answer to this question?
0.5 mole per litre
Why is this the correct answer?
Molarity is the number of moles of solute per litre of final solution. The glucose amount is n = 36 g ÷ 180 g mol−1 = 0.20 mol. Convert the final volume: 400 mL = 0.400 L. Hence M = 0.20 ÷ 0.400 = 0.50 mol L−1, so option A is correct. Using the water volume instead of final solution volume would be incorrect.
Which subject and chapter does this question cover?
This is a Class 11 Chemistry question. Chapter: Chapter 01: Solutions.
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