Question

The equation for the reaction of methane with oxygen (i.e. burning) is:

\[\ce{\underset{(g)}{CH4} + \underset{(g)}{2O2} -> \underset{(g)}{CO2} + \underset{(l)}{2H2O}}\]

1. How many moles of CO₂ will be produced when 4 moles of CH₄ will be burnt?
2. Find out the mass of H₂O produced in this reaction.
3. Find out the volume of oxygen required to burn completely 40 ml of methane at STP?

Answer 1

a. According to the equation, 1 mole of CH₄ produces 1 mole of CO₂.

Therefore, 4 moles of CH₄ will produce:

`"4 moles of CH"_4 xx ("1 mole of CO"_2)/("1 mole of CH"_4)` = 4 moles of CC

b. 1 mole of CH₄ produces 2 moles of H₂O.

4 moles of CH₄ × 2 = 8 moles of H₂O.

Molar mass of H₂O = (2 × 1) + 16 = 18 g/mol

Mass = 8 moles × 18 g/mol

Mass = 144 g

c. Volume of O2 = 40 ml of CH₄ × `("2 ml of O"_2)/("1 ml of CH"_4)`

= 80 ml