Two molecules of hydrogen and one molecule of oxygen reacts to give __ molecule(s) of water.
2
Two molecules of hydrogen and one molecule of oxygen reacts to give 2 molecule(s) of water.
Let us see how:
First, let us write the skeletal equation
H2+O2→H2O
∵ there are 2 oxygen atoms in the reactants side, multiply H2O by 2.
H2+O2→2H2O
∵there are 4 hydrogen atoms in the products side, multiply H2 hy 2
Finally, the required reaction is: 2H2+O2→2H2O