Question

what will happen if fresh grapes are kept in concentrated sugar solution (2) plant leaves are boiled and then a drop of concentrated sugar solution is added on the boiled leaves

Answer 1

This question is testing the concept of hypertonic and isotonic solution.

A hypertonic solution has more solute molecules and hence a high osmotic pressure.

An hypotonic solution has more solvent molecules hence low osmotic pressure.

OBSERVATIONS AND EXPLANATION ON THE TWO EXPERIMENTS

1.) The grapes shrink in other words they become flaccid.

This is because the concentrated sugar solution is hypertonic to the grape cells hence draws water from the cells by osmosis causing the cytoplasm of the grape cells to shrink.

2.) We will not observe any change on the leaves.

When the leaves are boiled, the cells of the leaves die. Osmosis thus cannot take place in dead cells.

Answer 2

The very strong sugar solution is an example of a hypertonic solution. In this the water will move down concentration gradient from high concentration to low concentration i.e.from grape to the solution .