For the reaction 2H2O > 2H2 + O2 what is the total number of moles of O2 produced from the complete decomposition of 8 moles H2O.

b - 3 moles

c - 4 moles

d - 8moles

Answer: Option C) 4 moles

Explanation:

The reaction below shows the decomposition of 2 moles of water to yeild 2 moles of hydrogen and 1 mole of oxygen respectively.

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

So, if 2 moles of H2O produce 1 mole of O2

8 moles of H2O will produce Z mole of O2

To get the value of Z, cross multiply

2 x Z = 1 x 8

2Z = 8

Z = 8/2

Z = 4

Thus, 4 moles of O2 is produced from the complete decomposition of 8 moles H2O.