what the total volume of gas(at STP)is produced by the electrolysis of 4 moles of H2O?

Question

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

Answer 1

2 H2O ===> 2 H2 + O2 or,

4 H2O ===> 4 H2 + 2 O2

So, from four moles of water, you'd get 6 moles of gas.

I mole of gas occupies 22.4 liters at STP, so:

6 moles x 22.4 liters/mole = 134.40 liters

Answer 2

1 mol of any gas at STP is always 22.4L. So simply multiply 22.4 by 4 and your answer is 89.6.