Question

The ratio of heats liberated at $298K$ from the combustion of one kg of coke and by burning water gas obtained from kg of coke is :

Given: Enthalpies of combustion of $C,CO$ and $H_2$ as $393.5kJ,285kJ,285kJ$ respectively all at $298K$. (Assume coke to be $100$% carbon).

• A. $0.69:1$
• B. $0.96:1$
• C. $0.79:1$
• D. $0.86:1$

Answer 1

The correct option is A $0.69:1$

The ratio of heats liberated at 298K from the combustion of one kg of coke and by burning water gas obtained from kg of coke

$=\frac{\text{enthalpy of combustion of C}}{\text{enthalpy of combustion of CO}+\text{enthalpy of combustion of hydrogen}}=$ $\frac{393.5}{285+285}=0.69:1$