Question

What mass of oxygen is needed for the complete combustion of 6.00×10⁻³ g

g of methane?

Answer 1

CH₄ + 2O₂ → CO₂ + 2H₂O

M(CH4) = 16 g/mol

n(CH4) $= \frac{6.00 \times 10^{-3}}{16} = 0.375 \times 10^{-3} \; mol$

According to the reaction:

n(O₂) = 2n(CH₄) $= 2 \times 0.375 \times 10^{-3} = 0.75 \times 10^{-3} \;mol$

M(O₂) = 32 g/mol

m(O₂) $= 0.75 \times 10^{-3} \times 32 = 24 \times 10^{-3} = 0.024 \;g$

Answer: 0.024 g