300 g water is added to 100 g of a 20 percent by mass solution. What is the new mass percent?
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Answer and explanation
Correct answer: 5 percent
The original 100 g solution contains 20 g solute because it is 20% by mass. Adding 300 g water does not change the solute mass, so it remains 20 g. The new total mass is 100 + 300 = 400 g. New mass percent = (20/400) × 100 = 5%. Dilution lowers percentage by increasing the denominator.
Frequently asked questions
What is the correct answer to this question?
5 percent
Why is this the correct answer?
The original 100 g solution contains 20 g solute because it is 20% by mass. Adding 300 g water does not change the solute mass, so it remains 20 g. The new total mass is 100 + 300 = 400 g. New mass percent = (20/400) × 100 = 5%. Dilution lowers percentage by increasing the denominator.
Which subject and chapter does this question cover?
This is a Class 11 Chemistry question. Chapter: Chapter 01: Solutions.
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