Question

2h2 o2 -> 2h2o how many grams of o2 and h2 were reacted to produce 30.0 g of h2o?

Answer 1

Molar mass:

H₂ = 2.0 g/mol
H₂O = 18.0 g/mol
O₂ = 32.0 g/mol

2 H₂ + O₂ =  2 H₂O

2 x 2 g H₂ ------------ 2 x 18.0 g H₂O
?? H₂ ------------------ 30 g H₂O

( 30 x 2 x 2 ) / 2 x 18.0 => 120 / 36 => 3.33 g of H₂

32 g O₂ ---------- 36.0 g H₂O
?? g O₂ ----------- 30.0 g H₂O

30.0 x 32 / 36.0 => 960 / 36.0 => 26.66 g of O₂