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प्रश्न
Define the Standard enthalpy of combustion.
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उत्तर
The standard enthalpy of combustion of a substance is the standard enthalpy change accompanying a reaction in which one mole of the substance in its standard state is completely oxidised.
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संबंधित प्रश्न
Answer the following in one or two sentences.
What is standard state of a substance?
Answer the following question.
State Hess’s law of constant heat summation. Illustrate with an example. State its applications.
The standard enthalpy of formation of water is - 286 kJ mol-1. Calculate the enthalpy change for the formation of 0.018 kg of water.
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Define the Bond enthalpy.
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\[\ce{2Fe_{(s)} + \frac{3}{2} O_{2(g)} -> Fe2O_{3(s)}}\]
Given:
| 1. | \[\ce{2Al_{(s)} + Fe2O_{3(s)} -> 2Fe_{(s)} + Al_2O_{3(s)}}\], | ∆rH° = –847.6 kJ |
| 2. | \[\ce{2Al_{(s)} + \frac{3}{2} O_{2(g)} -> Al2O_{3(s)}}\], | ∆rH° = –1670 kJ |
Define the Enthalpy of ionisation.
Write an application of Hess’s law.
Does the following reaction represent a thermochemical equation?
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The heat of formations of CO(g) and CO2(g) are −26.4 kcal and −94.0 kcal respectively. The heat of combustion of carbon monoxide will be ____________.
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∆H for the reaction
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Combustion of glucose takes place as
\[\ce{C6H12O6_{(s)} + 6O2_{(g)} -> 6CO2_{(g)} + 6H2O_{(g)}}\]; ΔH = −72 kcal mol−1
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An ideal gas expands isothermally and reversibly from 10 m3 to 20 m3 at 300 K performing 5 .187 kJ of work on surrounding. Calculate number of moles of gas undergoing expansion. (R = 8.314 J K-1 mol-1)
Calculate the standard enthalpy of formation of CH3OH(l) from the following data:
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Standard enthalpy of combustion of a substance is given. Then Write thermochemical equation.
ΔcH0[CH3CHO(l)] = - 1166 kJ mol-1
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For the reaction, aA + bB → cC + dD, write the expression for enthalpy change of reaction in terms of enthalpies of formation of reactants and products.
Calculate ΔsubH of the H2O from the given data:
\[\ce{H2O_{(s)}->H2O_{(l)},}\] ΔfusH = 6.01kJ mol−1
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Calculate the standard enthalpy of combustion of methane if the standard enthalpy of formation of methane, carbon dioxide and water are −74.8, −393.5 and −285.8 kJmol−1 respectively.
