If 200 ml of water is evaporated from 400 ml of 0.5 m aqueous salt solution, what is the resulting concentration? 1. 2.5 × 10−1 m 2. 2.5 × 101 m 3. 2.5 × 100 m 4. 2.5 × 10−2 m 5. none of these

None of these

Explanation:

Using the dilution formula;

M1V1 = M2V2

where M1 is the initial concentration, V1 is the initial volume, M2 is the concentration attained while V2 is the new volume.

Therefore;

M2 = M1V1/V2

     = (400 mL × 0.5) / 200 mL

     = 1 M

Therefore, the resulting concentration is 1M

Thus, the correct answer is "none of these"

idk what the question is about