Write down the reaction between `H_(2)O_(2)` and hydrazine `(NH_(2)NH_(2))` in the presence of Cu(II) catalyst. Mention the use of this reaction.

Explanation

A highly concentrated solution (about 40%) of `H_(2)O_(2)` (called high test peroxide ) oxidises hydrazine `(N_(2) H_(4))` in presence of Cu(II) into nitrogen gas, itself being oxidised to water (steam).
`overset(-2)(N_(2))H_(4)(l) + 2H_(2)overset(-1)(O_(2))(l)overset("Cu(II)")underset("catalyst")(rarr) overset(0)(N_(2) (g) + 4H_(2)overset(-2)(O)(g) +`heat
The reaction is highly exothermic and is accompanied by a large increase in volume which in turn generates high pressure. Due to this, reaction is employed for propelling rockets.