Find out the heat evolved in combustion if 112 litre (at 1 atm, 273 K) of water gas (mixture of equal volume of `H_(2)(g)` and CO(g)) is combusted with excess oxygen.
`H_(2)(g)+(1)/(2)O_(2)(g)rarrH_(2)O(g), Delta=-241.8 kJ` `CO(g)+(1)/(2)O_(2)(g)rarrCO_(2)(g), Delta=-283 kJ`

Options

A. `- 1414 . 0 kJ`
B. `-1209.0 kJ`
C. `- 1312.0 kJ`
D. `- 524.8 kJ`

Answer

c

Explanation

`H_(2)+(1)/(2) O_(2) rarr H_(2)O, DeltaH =- 241.8kJ`
`CO +(1)/(2) O_(2) rarr CO_(2), DeltaH = - 283kJ`
Since, `H_(2)` and CO have same volume in the mixture, therefore, each `= 56L `
`DeltaH` for combustion of `56L ` of `H_(2)`
`= -( 241.8) /( 22.40 xx56kJ = - 604.5 kJ`
`DeltaH` for combustionof `56 L ` of CO
`= - ( 283)/( 22.4) xx 56 kJ = - 707 .5 kJ`
`:. `Total `DeltaH = - 604 + ( - 707.5) = -1312kJ`