JEE Advanced 2020 Full Test 7 Paper 2

The balanced chemical equation is

CH4

1‌mol

+2

O2

2‌mol

⟶

CO2

1‌mol

+2H2O
16gm‌‌2×22.4L‌‌22.4L
44gm
No. of moles of CH4=‌

8

16

=0.5mol
No. of moles of O2=‌

4.48L

22.4L

=0.2mol
Now since 1 mole of CH4 requires 2 mol (i.e. 44.8L) of O2 for complete combustion. But the given moles of O2 is only 0.2mol.So,O2 is the limiting reagent.
Again, since 2 moles of O2 reacts with 1mol of CH4 to give 22.4L of CO2 at STP.
So 0.2 mole of O2 will react with 0.1mol of CH4 to give 2.24L of CO2.
Wt. of CO2 produced =0.1mol×44=4.4gms of CO2