Answer:
Mass = 7.2 g
Step-by-step explanation:
Given data:
Mass of water produced = ?
Mass of oxygen = 7.8 g
Solution:
Chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of oxygen:
Number of moles = mass/ molar mass
Number of moles = 7.8 g/ 32 g/mol
Number of moles = 0.2 mol
Now we will compare the moles of water with oxygen.
O₂ : H₂O
1 : 2
0.2 : 2×0.2 = 0.4 mol
Mass of water:
Mass = number of moles × number of moles
Mass = 0.4 mol × 18 g/mol
Mass = 7.2 g