What is weak and strong acids and also give  some  example  of weak and strong acids

Strong acid is the acid which get 100% or completely ionised in water. Example of strong acid is HCl.

All hydrogen chloride molecules become hydrogen ions and chloride ions when they are dissolved in water.

HCl(aq) (in water) → H⁺(aq) + Cl^-(aq)

 

Weak acid is partly or less than 100% ionised when dissolved in water. Example of weak acid is acetic caid.

 

Some of the molecules of acetic caid get ionised in water but most of then remains stay as molecules. The reaction for ionisation of weak acid is represented by using reversible arrow.