Answer:
5.76g
Step-by-step explanation:
2H2 + O2 => 2H2O
Molar mass of H2O = 18g/Mol
No of mole of H2O = 6.42/18 = 0.36 moles of water.
1 mole of O2 gives 2 moles of water.
Xmole of O2 gives 0.36 moles of water.
X = 0.36/2 = 0.18 mole
Molar mass of O2 = 32g/mol
Mass = 32 × 0.18 = 5.76g.