while doing the experiment of collecting dihydrogen gas in tube with adding zinc granules , when hydrogen gas is collected in tube filled with water , why water level goes down
Dear Student,
When an inverted glass tube is dipped in water and Zn granules is reacted with HCl, hydrogen gas is evolved. The hydrogen gas is lighter than water, so the gas starts collecting in the tube filled with water. This replaces the water present in tube. Thus, as the reaction proceeds, the gas fills in tube, water gets replaced and thus water level goes down. The space occupied by water is now occupied by hydrogen gas. We can not see the gas, we just see the decreasing level of water. But it is evident that hydrogen gas is being formed.
Regards
When an inverted glass tube is dipped in water and Zn granules is reacted with HCl, hydrogen gas is evolved. The hydrogen gas is lighter than water, so the gas starts collecting in the tube filled with water. This replaces the water present in tube. Thus, as the reaction proceeds, the gas fills in tube, water gets replaced and thus water level goes down. The space occupied by water is now occupied by hydrogen gas. We can not see the gas, we just see the decreasing level of water. But it is evident that hydrogen gas is being formed.
Regards