Question

How much water should be added to 20 ml of 20 % m/v glucose solution to make it 15 % m/v?

Answer 1

Answer: 80 ml

Step-by-step explanation:

V= vol ml, C = concentration %

V1 = 20ml, C1 = 20%

V2 = ? , C2 = 5%

V1C1 = V2C2

V2 = (V1C1)/C2

V2 = (20ml x 20%) / 5% = 80 ml