Question

an egg without shell placed in pure water for 5 minutes give reason

Answer 1

Osmosis happens when a solvent, like distilled water, diffuses across a membrane into a solution that has a higher concentration of some solute, like salt water.

Eggs are a model system for demonstrating osmosis because the thin membrane that lies underneath the shell is permeable to water.

So when it is placed in distilled water then the water from inside the cell, i.e., the egg, moves out because the concentration is more inside the egg cell.
As a result, the egg will swell and a time will come when it will burst.