Answer to Question #108903 in General Chemistry for Yaitza

Question

How many grams of O2 gas would you need to make 100grams of water?(H2O)

How many grams of H2 would you need to make 100grams of water?

Answer 1

The equation for the reaction of the formation of water from oxygen and hydrogen:

2H₂ + O₂ $\to$ 2H₂O

• According to the equation, we can determine the amounts of substances of H₂ and O₂:

$\nu$(H₂O) = $m/M$ = 100(g) / 18(g/mol) = 5.56 mol = $\nu$(H₂)

$\nu$ (O₂) = $\nu$ (H₂O) $• 1/2$ = 5.56(mol) • 1/2 = 2.78(mol)

• Then, we can calculate the masses of hydrogen and oxygen:

m(O₂) = $\nu • M$ = 2.78(mol) • 32(g/mol) = 88.96 g

m(H₂) = $\nu•M =$ 5.56(mol) • 2(g/mol) = 11.12 g

Answer: m(O₂)=88.96 g; m(H₂) = 11.12 g