10 g sodium chloride is dissolved in 90 g water. What is the mass percent of sodium chloride?
Answer and explanation
Correct answer: 10%
Mass percent is defined as the mass of the solute divided by the mass of the entire solution, multiplied by 100. The solution mass is 10 g NaCl + 90 g water = 100 g. Thus, mass percent of NaCl = (10/100) × 100 = 10%. Option B is correct. Dividing by 90 g would use only the solvent mass, and 90% represents the water percentage, not the NaCl percentage.
Frequently asked questions
What is the correct answer to this question?
10%
Why is this the correct answer?
Mass percent is defined as the mass of the solute divided by the mass of the entire solution, multiplied by 100. The solution mass is 10 g NaCl + 90 g water = 100 g. Thus, mass percent of NaCl = (10/100) × 100 = 10%. Option B is correct. Dividing by 90 g would use only the solvent mass, and 90% represents the water percentage, not the NaCl percentage.
Which subject and chapter does this question cover?
This is a Class 11 Chemistry question. Chapter: Chapter 01: Solutions.
