Question

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 1

Answer: 4

Explanation: The equation tells you that the mole ratio of O2 produced from H2O is 1:2 (1 mole of O2 for every 1 moleH2O). If 8 moles of water are decomposed, then 4 moles of O2 would be produced.

8 moles water (1 mole oxygen/2 moles water) = 4 moles oxygen

Answer 2

Answer: Option C) 4 moles

Step-by-step 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 .