Why is the amount of gas collected in one of the test tubes in Activity 1.7 double the amount collected in the other? Name this gas.

In activity 1.7, gas collected in one of the test tubes is double of the amount collected in the other because water gets hydrolysed to release H₂ and O₂ gas. Here, after electrolysis two molecules of Hydrogen and one molecule of oxygen gas are released; hence, the amount of Hydrogen collected would be double than that of oxygen.