Question

A !32 gaseous mixture contains C2H6 , C3H8 and N2 gases in molar ratio 2:1:1. If carbon
atoms present in the mixture are the only source of C for the formation of C7H16 .What
amount of C7H16 in gram will be obtained.
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Answer 1

Answer:

From the given ratio we can get the masses of the two compounds.

From the ratio the mass of CH₄ will be :

5/7 × 280 = 200 g

The mass of C₂H₆ will be :

2/7 × 280 = 80 g

Equation for combustion of both is :

CH₄ + 2O₂ —> CO₂ + 2 H₂O

The moles of CH₄ are :

200 / 16 = 12.5 moles.

The mole ratio of CH₄ to CO₂ is 1 : 1 and hence moles of CO₂ are 12.5 moles.

C₂H₆ + 3.5O₂ —> 2CO₂ (g) + 3H₂O

Moles of C₂H₆ are :

80/30 = 2.667 moles.

The mole ratio is 1 : 2

Moles of CO₂ will be :

2 × 2.667 = 5.334 moles.

Total moles :

5.334 + 12.5 = 17.834 moles