An electrolytic decomposition reaction is a type of decomposition reaction in which the activation energy for decomposition is provided in the form of electrical energy. An example of an electrolytic decomposition reaction is the electrolysis of water shown below. If 18 g of water is subjected to an electrolytic decomposition reaction, what mass of oxygen will be produced?

Note: Balance the equation before solving the problem

H2O→H2+ O2

(Molar masss: O = 16 g/mol; H =1 g/mol)

1 answer

The balanced equation for the electrolysis of water is:

2 H2O → 2 H2 + O2

From the balanced equation, we can see that for every 2 moles of water decomposed, 1 mole of oxygen is produced.

To find the mass of oxygen produced from 18 g of water, we need to first find the number of moles of water present:

18 g H2O x (1 mole H2O / 18 g H2O) = 1 mole H2O

So we have 1 mole of water, which means we can produce:

1 mole H2O x (1 mole O2 / 2 mole H2O) = 0.5 moles O2

Finally, we can calculate the mass of oxygen produced using its molar mass:

0.5 moles O2 x 16 g/mol = 8 g O2

Therefore, 8 g of oxygen will be produced from 18 g of water in an electrolytic decomposition reaction.