Isotonic solutions are the solutions that have same concentration' of water and solutes. Cells placed in isotonic solutions will never shrink or swell. (A) Strength of 18g∕L glucose =
18
180
=
1
10
Strength of 6g∕L urea =
6
60
=
1
10
∴18g∕L glucose is isotonic with 6g∕L urea. (B) Strength of 10g∕L glucose =
10
180
Strength of 10g∕L urea =
10
60
(C) The van't Hoff factor for NaOH=2. Due to 2 ions are produced, Na+and OH−. So strength of NaOH=2×0.01=0.02M Strength of glucose =0.02M Therefore, (A) and (C) are isotonic solutions.
