Advertisements
Advertisements
Question
Write the expression showing the relation between enthalpy change and internal energy change for gaseous phase reaction.
Solution
∆H = ∆U + ∆ng RT
where ∆H is change in enthalpy,
∆U is a change in internal energy,
Δng is the difference between the number of moles of products and those of reactants.
APPEARS IN
RELATED QUESTIONS
Answer in brief.
Obtain the expression for work done in chemical reaction.
Answer the following question.
Calculate standard enthalpy of reaction,
Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g), from the following data.
Δf H°(Fe2O3) = - 824 kJ/mol,
Δf H°(CO) = - 110 kJ/mol,
Δf H°(CO2) = - 393 kJ/mol
Answer the following question.
Calculate ΔU at 298 K for the reaction,
C2H4(g) + HCl(g) → C2H5Cl(g), ΔH = - 72.3 kJ
How much PV work is done?
Calculate the amount of work done in the
1) Oxidation of 1 mole HCl(g) at 200 °C according to reaction.
4HCl(g) + O2(g) → 2Cl2(g) + 2H2O(g)
2) Decomposition of one mole of NO at 300 °C for the reaction
2NO(g) → N2(g) + O2(g)
Answer the following question.
When 6.0 g of O2 reacts with CIF as per
\[\ce{2ClF_{(g)} + O2_{(g)} -> Cl2O_{(g)} + OF2_{(g)}}\]
The enthalpy change is 38.55 kJ. What is the standard enthalpy of the reaction? (Δr H° = 205.6 kJ)
An ideal gas expands from the volume of 1 × 10–3 m3 to 1 × 10–2 m3 at 300 K against a constant pressure at 1 × 105 Nm–2. The work done is
Define enthalpy of combustion.
Define enthalpy of neutralization.
Enthalpy of neutralization is always a constant when a strong acid is neutralized by a strong base: account for the statement.
Calculate the enthalpy change for the reaction \[\ce{Fe2O3 + 3CO -> 2Fe + 3CO2}\] from the following data.
\[\ce{2Fe + 3/2O2 -> Fe2O3}\]; ΔH = −741 kJ
\[\ce{C + 1/2O2 -> CO}\]; ΔH = −137 kJ
\[\ce{C + O2-> CO2}\]; ΔH = −394.5 kJ
The standard enthalpies of formation of SO2 and SO3 are −297 kJ mol−1 and −396 kJ mol−1 respectively. Calculate the standard enthalpy of reaction for the reaction: \[\ce{SO2 + 1/2O2 -> SO3}\]
The difference between heats of reaction at constant pressure and at constanl volume for the reaction
\[\ce{2C6H6_{(l)} + 15O2_{(g)} -> 12CO2_{(g)} + 6H2O_{(l)}}\] at 25°C in kJ
When 6.0 g of O2 reacts with CIF as per \[\ce{2ClF_{(g)} + O2_{(g)} -> Cl2O_{(g)} + OF2_{(g)}}\] the enthalpy change is 38.55 kJ. The standard enthalpy of the reaction is ____________.
When 4 g of iron is burnt to ferric oxide at constant pressure, 29.28 kJ of heat is evolved. What is the enthalpy of formation of ferric oxide?
(Atomic mass of Fe = 56)
The enthalpy change for two reactions are given by the equations
\[\ce{2Cr_{(s)} + 1.5 O2_{(g)} -> Cr2O3_{(s)}}\];
∆H1 = −1130 kJ ............(i)
\[\ce{C_{(s)} + 0.5 O2_{(g)} -> CO_{(g)}}\];
∆H2 = −110 kJ .........(ii)
What is the enthalpy change, in kJ, for the following reaction?
\[\ce{3C_{(s)} + Cr2O3_{(s)} -> 2Cr_{(s)} + 3CO_{(g)}}\]
In which of the following reactions does the heat change represent the heat of formation of water?
In which of the following reactions, ∆H is greater than ∆U?
Work done when 2 moles of an ideal gas is compressed from a volume of 5 m3 to 1 dm3 at 300 K, under a pressure of 100 kPa is ____________.
For the reaction, \[\ce{A_{(s)} + 2B_{(g)} -> 5C_{(s)} + D_{(l)}}\], ∆H and ∆U are related as ____________.
In which of the following reactions, ΔH is not equal to ΔU?
What is the amount of work done when 0.5 mole of methane, CH4 (g), is subjected to combustion at 300 K? (Given, R = 8.314 JK-1mol-1)
Calculate the work done during the combustion of 0.138 kg of ethanol, C2H5OH(l) at 300 K.
Given: R = 8.314 Jk−1 mol−1, molar mass of ethanol = 46 g mol−1.
Under what conditions ΔH = ΔU?
Define enthalpy.