Answer:
The answer to your question is 67.5 g of H₂O
Explanation:
Data
mass of water = ?
mass of H₂ = 7.51 g
mass of O₂ = excess
Balanced chemical reaction
2H₂ + O₂ ⇒ 2H₂O
Process
1.- Calculate the molar mass of H₂ and H₂O
H₂ = 2(1 x 2) = 4 g
H₂O = 2[(2 x 1) + (16 x 1)] = 2[18] = 36 g
2.- Use proportions and cross multiplication to find the answer
4 g of H₂ ------------------ 36 g of H₂O
7.5 g of H₂ ----------------- x
x = (7.5 x 36) / 4
x = 270 / 4
x = 67.5 g of H₂O
