Question

Number of moles of oxygen needed to produce 4 moles of water on reacting with 4 moles of hydrogen gas is _____ ? Options a) 1 moles b) 2 moles c) 3 moles d) 4 moles.

Answer 1

the answer is 2 moles

Answer 2

the balanced chemical equation for this synthesis reaction looks like this.
2H2(g]+O2(g]→2H2O(l]]
Notice that the reaction requires 2 moles of hydrogen gas and 1 mole of oxygen gas to produce 2 moles of water