Question

Explain the laboratory preparation of oxygen with hydrogen peroxide (H_{​​​​​​2}​​​​​O_{​​​​2}) and manganese dioxide (MnO_{​​​​2}).

Answer 1

Manganese dioxide catalyzes the decomposition of hydrogen peroxide.
Hydrogen peroxide($H_2{O}_2$), decomposes naturally at a very slow rate to form oxygen gas and water. When manganese dioxide($Mn{O}_2$), is added to a solution of hydrogen peroxide, the rate of the reaction increases significantly. Manganese dioxide acts as a catalyst for the decomposition of hydrogen peroxide, meaning that it is not consumed in the reaction.
The balanced chemical equation for this reaction:
$H_2{O}_2\underrightarrow{\Delta ,Mn{O}_2}2H_{2}O+O_2$