Question

During laboratory preparation of oxygen by hydrogen peroxide and potassium chlorate, the gas is collected by $- - - -$ displacement of water.
(A) Downward, upward
(B) Upward
(C) Downward
(D) Upward, downward

Answer 1

Oxygen can be prepared from the hydrogen peroxide and potassium chlorate in which gas is collected by downward displacement of water.

Complete step by step answer:
Oxygen can be made from hydrogen peroxide, which decomposes slowly to form water and oxygen. The rate of reaction can be increased by using a catalyst, manganese $\left( {IV} \right)$ oxide. When manganese $\left( {IV} \right)$ oxides are added to hydrogen peroxide, bubbles of oxygen are given off.
It is the point to be noted that during laboratory preparation of oxygen by hydrogen peroxide and potassium chlorate, the gas is collected by downward displacement of water.
${H_2}{O_2}$ is preferred for lab preparation of oxygen because of following reasons:
1. No heating is required
2. The rate of evolution of oxygen $\left( {{O_2}} \right)$ is moderate and under control.
${H_2}{O_2}$ is a safe chemical.
Additional information:
When the catalase comes into contact with hydrogen peroxide $\left( {{H_2}{O_2}} \right)$ into water $\left( {{H_2}O} \right)$ and oxygen gas $\left( {{O_2}} \right)$. Catalase does this extremely efficiently up to $200,000$ reactions per second. The bubbles you see in the foam are pure oxygen bubbles being created by the catalase.

Note:
So overall, hydrogen peroxide can be used in liquid form, gas or vapor form but also as a condensed gas. While the gas form is essentially ‘dry’ the condensed gas form is considered ‘wet’.