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Standard enthaies of combustion for H(2)...

Standard enthaies of combustion for `H_(2) (g), CO(G), CH_(4) (g)`, and `C_(6) H_(12) O_(6) (s)` are -258, - 283, - 890, and `- 2802 kJ mol^(-1)`, respectively. Which of the following has minimum colorific value?

A

`C_(6) H_(12) O_(6) (s)`

B

`CH_(4) (g)`

C

`CO (g)`

D

`H_(2) (g)`

Text Solution

Verified by Experts

The correct Answer is:
C
The caloriffic value `(CV)` of a fuel or food is the standard enthalpy of combustion per gram of the substance, i.e., the amount of heat released when one gram of the substance undergoes complete combustion. This,
`CV (C_(6) H_(12) O_(6)) = (- 2802)/(180) = - 15.6 kJ g^(-1)`
`CV (CH_(4)) = (- 890)/(16) = - 55.6 kJ g^(-1)`
`CV (CO) = (- 283)/(28) = - 10.1 kJ g^(-1)`
`CV (H_(2)) = (-285)/(2) = - 142.5 kJ g^(-)`
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