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प्रश्न
ΔU⊖of combustion of methane is – X kJ mol–1. The value of ΔH⊖ is ______.
विकल्प
= ΔU⊖
> ΔU⊖
< ΔU⊖
= 0
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उत्तर
ΔU⊖of combustion of methane is – X kJ mol–1. The value of ΔH⊖ is < ΔU⊖.
Explanation:
Since ΔH⊖ = ΔU⊖ + ΔngRT and ΔU⊖ = - X kJ mol-1,
ΔH⊖ = (- X) + ΔngRT.
⇒ ΔH⊖ < ΔU⊖
संबंधित प्रश्न
The enthalpy of combustion of methane, graphite and dihydrogen at 298 K are, - 890.3 kJ mol-1 -393.5 kJ mol-1, and - 285.8 kJ mol-1 respectively. Enthalpy of formation of CH4(g) will be ______.
Assertion (A): Combustion of all organic compounds is an exothermic reaction.
Reason (R): The enthalpies of all elements in their standard state are zero.
Standard enthalpy of combustion at 25°C of hydrogen, cyclohexene (C6H10) and cyclohexane (C6H12) are – 240, – 3800 and – 3920 kJ/mol respectively. The heat of hydrogenation of cyclohexene is ______.
At 25°C and 1 atm pressure, the enthalpies of combustion are as given below:
| Substance | H2 | C (graphite) | C2H6(g) |
| `(Δ_"c""H"°)/"kJ mol"^-1` | −286 | −394 | −1560 |
The enthalpy of the formation of ethane is:
