Question

At 300 K and 1 atmospheric pressure, 10 mL of a
hydrocarbon required 55 mL of O2 for complete
combustion, and 40 mL of CO2 is formed. The
formula of the hydrocarbon is
(a) C4H10
(b) C4H8
(c) C4&H7 CI
(d) C4&H6

(JEE Main 2019)

Answer 1

Answer:

C4H6

Explanation:

Reaction: A+B --- C +D  

CₓH₄ (g) + (x+ y/4) O₂------ x CO₂ (g) + 4/2 H₂O

Hydrocarbon + Oxygen--- Carbon dioxide + Water

10ml  55 ml  40 ml

Hence

1 mL of hydrocarbon = x mL of CO₂ is produced

According to the equation

10 ml (x) ml of CO₂

Therefore, 10 x = 40 ml

X = 4

(x+y/4) ml of O₂ is required = x mL of CO₂

55 mL = x/(x+y/4) x 55 ml of CO₂

According to equation

x/(x+y/4) x 55 = 40

55x =40x +10y

15x = 10 y

15 x 4 = 10 y

60/10 = y

Y=6

Therefore the compound is C4H6