Answer:
0.218 mol.
Step-by-step explanation:
- Firstly, we need to write the balanced reaction:
CH₄ + 2O₂ → CO₂ + 2H₂O,
It is clear that 1 mol of CH₄ reacts with 2 mol of O₂ to produce 1 mol of CO₂ and 2 mol of H₂O.
- We need to calculate the no. of moles of 7.84 g H₂O:
n = mass/molar mass = (7.84 g)/(18.0 g/mol) = 0.436 mol.
Using cross multiplication:
1 mol of CH₄ is needed to produce → 2 mol of H₂O, from stichiometry.
??? mol of CH₄ is needed to produce → 0.436 mol of H₂O.
∴ The no. of moles of CH₄ = (1 mol)(0.435 mol)/(2 mol) = 0.218 mol.