In the electrolysis of water 75.0 cm3 of oxygen gas are produced.How many cm3 of hydrogen are produced ?

To find the volume of hydrogen gas produced in the electrolysis of water, we need to know the stoichiometry of the reaction. The balanced equation for the electrolysis of water is as follows:

2H2O(l) -> 2H2(g) + O2(g)

According to the stoichiometry of the reaction, for every 2 moles of water molecules decomposed, we obtain 2 moles of hydrogen gas and 1 mole of oxygen gas.

To find the volume of hydrogen gas produced, we can use the following formula:

(Volume of hydrogen gas) / 2 = (Volume of oxygen gas)

Given that 75.0 cm3 of oxygen gas are produced, we can substitute this value into the formula and solve for the volume of hydrogen gas:

(Volume of hydrogen gas) / 2 = 75.0 cm3
Volume of hydrogen gas = 2 * 75.0 cm3
Volume of hydrogen gas = 150.0 cm3

Therefore, 150.0 cm3 of hydrogen gas are produced in the electrolysis of water.