Question

What mass of carbon dioxide is produced from the complete combustion of 4.00×10−3 g of methane?

Answer 1

Molar mass of CH4,
MM = 1*MM(C) + 4*MM(H)
= 1*12.01 + 4*1.008
= 16.042 g/mol


mass(CH4)= 4.00*10^-3 g = 0.004 g

number of mol of CH4,
n = mass of CH4/molar mass of CH4
=(0.004 g)/(16.042 g/mol)
= 2.493*10^-4 mol
Balanced chemical equation is:
CH4 + 2 O2 ---> CO2 + 2 H2O


Molar mass of CO2,
MM = 1*MM(C) + 2*MM(O)
= 1*12.01 + 2*16.0
= 44.01 g/mol

According to balanced equation
mol of CO2 formed = (1/1)* moles of CH4
= (1/1)*0.000249
= 0.000249 mol


mass of CO2 = number of mol * molar mass
= 2.493*10^-4*44.01
= 1.10*10^-2 g
Answer: 1.10*10^-2 g