Question

In isotonic solutions ________________.

• A. solute and solvent both are same.
• B. solute and solvent may or may not be same.
• C. solute is always same solvent may be different
• D. osmotic pressure is same.

Answer 1

Answer: (B), (D)

osmotic pressure is same.

Two solutions having the same osmotic pressure (at a given temperature) across a semi-permeable membrane are referred to as isotonic solutions.

The expression for osmotic pressure is given as: $\pi =CRT$
Where, $\pi$ = osmotic pressure

$C=$ concentration of solution

$T=$ Absolute temperature

Therefore, osmotic pressure is a function of concentration and temperature only.

• Due to the same osmotic pressure, the concentrations of the isotonic solutions remain the same.
• In isotonic solutions, the nature of the solute or the solvent may or may not be the same.
  

Thus, in isotonic solutions, osmotic pressure is the same, but the solute and the solvent may or may not be the same.

Hence, options (B) and (C) are the correct answers.