Question

One litre of water is evaporated from 6 litres of a solution containing 5% salt. The percentage of salt in the remaining solution is

• A. \(4(\frac{4}{9})\%\)
• B. \(5(\frac{5}{7})\%\)
• C. 0.05
• D. 0.06

Answer 1

The Correct Option is D

The problem requires finding the new percentage of salt after evaporating 1 litre of water from the original solution. Here's the solution:

1. Initial volume of the solution = 6 litres.
2. Concentration of salt = 5%, which means there are 5 grams of salt in every 100 grams of solution.
3. Total salt in the solution = 5% of 6 litres = 0.05 × 6 litres = 0.3 litres.
4. When 1 litre of water is evaporated, the remaining volume = 6 litres - 1 litre = 5 litres.
5. The amount of salt remains constant at 0.3 litres since salt does not evaporate.
6. Concentration of salt in the new solution = (Amount of salt / Volume of remaining solution) = 0.3 litres / 5 litres.
7. The percentage concentration of salt = \((\frac{0.3}{5}) \times 100\).
8. Simplifying gives: \((0.06) \times 100 = 6\%\).

Thus, the percentage of salt in the remaining solution is 6%. Therefore, the correct answer is

0.06

.