What is the connection between the relative gas volumes collected in the two tubes and the relative number of gas molecules in the tubes?

Answer : The hydrogen gas had twice the amount of molecules and was twice the volume of oxygen gas.

Explanation : When water decomposes into its component elements, hydrogen and oxygen, when an electrical current is passed through it. The volume of hydrogen, collected in the right test tube, is twice the volume of oxygen. The electrolysis experiment revealed that the moles of hydrogen gas molecules which evolved after the electrolysis experiment where in the twice volume of oxygen gas as there were two molecules of hydrogen present in the water molecule compared to only one oxygen molecule which was present.