Question

For the reaction: 2H2O2 → 2H2 + 2O2, what is the total number of moles of O2 produced from the complete decomposition of 8 moles H2O2?
A) 2 moles
B) 4 moles
C) 8 moles
D) 16 moles

Answer 1

C 8 moles as you can ÷ the reaction  by 2 since it all has a 2 coefficient so that means for every 1 mole of H2O2 you decompose you get one mole of O2 

Answer 2

Answer: C) 8 moles

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

$2H_2O_2\rightarrow 2H_2+2O_2$

According to stoichiometry of the given balanced equation:

2 moles of $H_2O_2$ decomposes to form 2 moles of $O_2$

Thus 8 moles of $H_2O_2$ decomposes to form=$\frac{2}{2}\times 8=8moles$ of $O_2$

Thus 8 moles of $O_2$ are produced from 8 moles of $H_2O_2$