5.85 g sodium chloride is dissolved to make 1 L of solution. Its molar mass is 58.5 g/mol. What is the molarity?
Answer and explanation
Correct answer: 0.1 mole per litre
Molarity is moles of solute per litre of final solution. The sodium chloride amount is n = 5.85 g/(58.5 g mol⁻¹) = 0.10 mol. Since the solution volume is exactly 1.00 L, M = 0.10 mol/1.00 L = 0.10 mol L⁻¹. Therefore option A is correct. Option B treats 5.85 g as one mole, C is ten times too small, and D is much too large.
Frequently asked questions
What is the correct answer to this question?
0.1 mole per litre
Why is this the correct answer?
Molarity is moles of solute per litre of final solution. The sodium chloride amount is n = 5.85 g/(58.5 g mol⁻¹) = 0.10 mol. Since the solution volume is exactly 1.00 L, M = 0.10 mol/1.00 L = 0.10 mol L⁻¹. Therefore option A is correct. Option B treats 5.85 g as one mole, C is ten times too small, and D is much too large.
Which subject and chapter does this question cover?
This is a Class 11 Chemistry question. Chapter: Chapter 01: Solutions.
