Heat of Reaction
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CHXI06:THERMODYNAMICS

369468 Thermodynamic standard conditions of temperature and pressure are

1 \(\mathrm{0^{\circ} \mathrm{C}}\) and \(\mathrm{101.3 \mathrm{kPa}}\)
2 \(\mathrm{298 \mathrm{~K}}\) and \(\mathrm{1 \mathrm{~atm}}\)
3 \(\mathrm{273 \mathrm{~K}}\) and \(\mathrm{101.3 \mathrm{kPa}}\)
4 \({\rm{0^\circ C}}{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} {\rm{1}}\;{\rm{atm}}{\rm{.}}\)
KCET - 2007
CHXI06:THERMODYNAMICS

369522 The standard enthalpy of formation \(\mathrm{\left(\Delta_{f} H_{298}^{o}\right)}\) for methane, \(\mathrm{\mathrm{CH}_{4}}\) is \(\mathrm{-74.9 \mathrm{~kJ} / \mathrm{mol}^{-1}}\). In order to calculate the average energy given out in the formation of a \(\mathrm{\mathrm{C}-\mathrm{H}}\) bond from this it is necessary to know which one of the following?

1 The dissociation energy of the hydrogen molecule, \(\mathrm{\mathrm{H}_{2}}\).
2 The first four ionisation energies of carbon.
3 The dissociation energy of \(\mathrm{H_{2}}\) and enthalpy of sublimation of carbon (graphite).
4 The first four ionisation energies of carbon and electron affinity of hydrogen.
JEE - 2014
CHXI06:THERMODYNAMICS

369523 The \(\mathrm{\mathrm{H}-\mathrm{H}}\) bond energy is \({\text{430}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\) and \({\text{Cl - Cl}}\) bond energy is \(\mathrm{240 \mathrm{kJmol}^{-1} . \Delta H}\) for \(\mathrm{\mathrm{HCl}}\) is\( - \,{\rm{90}}\;{\rm{kJ}}\). The \(\mathrm{\mathrm{H}-\mathrm{Cl}}\) bond energy is about

1 \({\text{425}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
2 \({\text{213}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
3 \({\text{306}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
4 \({\text{180}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
CHXI06:THERMODYNAMICS

369524 Which of the following statement(s) is correct?

1 Mean \(\mathrm{\mathrm{C}-\mathrm{H}}\) bond enthalpies differ slightly from compound to compound, as in \(\mathrm{\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Cl}, \mathrm{CH}_{3} \mathrm{NO}_{2}}\) etc. but it does not differ in a great deal.
2 The reaction enthalpies are very important quantities as these arise from the changes that accompany the breaking of old bonds and formation of the new bonds.
3 \(\mathrm{\Delta_{\mathrm{r}} \mathrm{H}^{\circ}=\sum}\) bond enthalpies of reactants \(\mathrm{-\sum}\) bond enthalpies of products.
4 All of the above.
CHXI06:THERMODYNAMICS

369525 Enthalpy change for the reaction, \(\mathrm{4 \mathrm{H}(\mathrm{g}) \longrightarrow 2 \mathrm{H}_{2}(\mathrm{~g})}\) is \(\mathrm{-869.6 \mathrm{~kJ}}\) the dissociation energy of \(\mathrm{\mathrm{H}-\mathrm{H}}\) bond is

1 \(\mathrm{+217.4 \mathrm{~kJ}}\)
2 \(\mathrm{-434.8 \mathrm{~kJ}}\)
3 \(\mathrm{-869.6 \mathrm{~kJ}}\)
4 \(\mathrm{+434.8 \mathrm{~kJ}}\)
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CHXI06:THERMODYNAMICS

369468 Thermodynamic standard conditions of temperature and pressure are

1 \(\mathrm{0^{\circ} \mathrm{C}}\) and \(\mathrm{101.3 \mathrm{kPa}}\)
2 \(\mathrm{298 \mathrm{~K}}\) and \(\mathrm{1 \mathrm{~atm}}\)
3 \(\mathrm{273 \mathrm{~K}}\) and \(\mathrm{101.3 \mathrm{kPa}}\)
4 \({\rm{0^\circ C}}{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} {\rm{1}}\;{\rm{atm}}{\rm{.}}\)
KCET - 2007
CHXI06:THERMODYNAMICS

369522 The standard enthalpy of formation \(\mathrm{\left(\Delta_{f} H_{298}^{o}\right)}\) for methane, \(\mathrm{\mathrm{CH}_{4}}\) is \(\mathrm{-74.9 \mathrm{~kJ} / \mathrm{mol}^{-1}}\). In order to calculate the average energy given out in the formation of a \(\mathrm{\mathrm{C}-\mathrm{H}}\) bond from this it is necessary to know which one of the following?

1 The dissociation energy of the hydrogen molecule, \(\mathrm{\mathrm{H}_{2}}\).
2 The first four ionisation energies of carbon.
3 The dissociation energy of \(\mathrm{H_{2}}\) and enthalpy of sublimation of carbon (graphite).
4 The first four ionisation energies of carbon and electron affinity of hydrogen.
JEE - 2014
CHXI06:THERMODYNAMICS

369523 The \(\mathrm{\mathrm{H}-\mathrm{H}}\) bond energy is \({\text{430}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\) and \({\text{Cl - Cl}}\) bond energy is \(\mathrm{240 \mathrm{kJmol}^{-1} . \Delta H}\) for \(\mathrm{\mathrm{HCl}}\) is\( - \,{\rm{90}}\;{\rm{kJ}}\). The \(\mathrm{\mathrm{H}-\mathrm{Cl}}\) bond energy is about

1 \({\text{425}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
2 \({\text{213}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
3 \({\text{306}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
4 \({\text{180}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
CHXI06:THERMODYNAMICS

369524 Which of the following statement(s) is correct?

1 Mean \(\mathrm{\mathrm{C}-\mathrm{H}}\) bond enthalpies differ slightly from compound to compound, as in \(\mathrm{\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Cl}, \mathrm{CH}_{3} \mathrm{NO}_{2}}\) etc. but it does not differ in a great deal.
2 The reaction enthalpies are very important quantities as these arise from the changes that accompany the breaking of old bonds and formation of the new bonds.
3 \(\mathrm{\Delta_{\mathrm{r}} \mathrm{H}^{\circ}=\sum}\) bond enthalpies of reactants \(\mathrm{-\sum}\) bond enthalpies of products.
4 All of the above.
CHXI06:THERMODYNAMICS

369525 Enthalpy change for the reaction, \(\mathrm{4 \mathrm{H}(\mathrm{g}) \longrightarrow 2 \mathrm{H}_{2}(\mathrm{~g})}\) is \(\mathrm{-869.6 \mathrm{~kJ}}\) the dissociation energy of \(\mathrm{\mathrm{H}-\mathrm{H}}\) bond is

1 \(\mathrm{+217.4 \mathrm{~kJ}}\)
2 \(\mathrm{-434.8 \mathrm{~kJ}}\)
3 \(\mathrm{-869.6 \mathrm{~kJ}}\)
4 \(\mathrm{+434.8 \mathrm{~kJ}}\)
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CHXI06:THERMODYNAMICS

369468 Thermodynamic standard conditions of temperature and pressure are

1 \(\mathrm{0^{\circ} \mathrm{C}}\) and \(\mathrm{101.3 \mathrm{kPa}}\)
2 \(\mathrm{298 \mathrm{~K}}\) and \(\mathrm{1 \mathrm{~atm}}\)
3 \(\mathrm{273 \mathrm{~K}}\) and \(\mathrm{101.3 \mathrm{kPa}}\)
4 \({\rm{0^\circ C}}{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} {\rm{1}}\;{\rm{atm}}{\rm{.}}\)
KCET - 2007
CHXI06:THERMODYNAMICS

369522 The standard enthalpy of formation \(\mathrm{\left(\Delta_{f} H_{298}^{o}\right)}\) for methane, \(\mathrm{\mathrm{CH}_{4}}\) is \(\mathrm{-74.9 \mathrm{~kJ} / \mathrm{mol}^{-1}}\). In order to calculate the average energy given out in the formation of a \(\mathrm{\mathrm{C}-\mathrm{H}}\) bond from this it is necessary to know which one of the following?

1 The dissociation energy of the hydrogen molecule, \(\mathrm{\mathrm{H}_{2}}\).
2 The first four ionisation energies of carbon.
3 The dissociation energy of \(\mathrm{H_{2}}\) and enthalpy of sublimation of carbon (graphite).
4 The first four ionisation energies of carbon and electron affinity of hydrogen.
JEE - 2014
CHXI06:THERMODYNAMICS

369523 The \(\mathrm{\mathrm{H}-\mathrm{H}}\) bond energy is \({\text{430}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\) and \({\text{Cl - Cl}}\) bond energy is \(\mathrm{240 \mathrm{kJmol}^{-1} . \Delta H}\) for \(\mathrm{\mathrm{HCl}}\) is\( - \,{\rm{90}}\;{\rm{kJ}}\). The \(\mathrm{\mathrm{H}-\mathrm{Cl}}\) bond energy is about

1 \({\text{425}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
2 \({\text{213}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
3 \({\text{306}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
4 \({\text{180}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
CHXI06:THERMODYNAMICS

369524 Which of the following statement(s) is correct?

1 Mean \(\mathrm{\mathrm{C}-\mathrm{H}}\) bond enthalpies differ slightly from compound to compound, as in \(\mathrm{\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Cl}, \mathrm{CH}_{3} \mathrm{NO}_{2}}\) etc. but it does not differ in a great deal.
2 The reaction enthalpies are very important quantities as these arise from the changes that accompany the breaking of old bonds and formation of the new bonds.
3 \(\mathrm{\Delta_{\mathrm{r}} \mathrm{H}^{\circ}=\sum}\) bond enthalpies of reactants \(\mathrm{-\sum}\) bond enthalpies of products.
4 All of the above.
CHXI06:THERMODYNAMICS

369525 Enthalpy change for the reaction, \(\mathrm{4 \mathrm{H}(\mathrm{g}) \longrightarrow 2 \mathrm{H}_{2}(\mathrm{~g})}\) is \(\mathrm{-869.6 \mathrm{~kJ}}\) the dissociation energy of \(\mathrm{\mathrm{H}-\mathrm{H}}\) bond is

1 \(\mathrm{+217.4 \mathrm{~kJ}}\)
2 \(\mathrm{-434.8 \mathrm{~kJ}}\)
3 \(\mathrm{-869.6 \mathrm{~kJ}}\)
4 \(\mathrm{+434.8 \mathrm{~kJ}}\)
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CHXI06:THERMODYNAMICS

369468 Thermodynamic standard conditions of temperature and pressure are

1 \(\mathrm{0^{\circ} \mathrm{C}}\) and \(\mathrm{101.3 \mathrm{kPa}}\)
2 \(\mathrm{298 \mathrm{~K}}\) and \(\mathrm{1 \mathrm{~atm}}\)
3 \(\mathrm{273 \mathrm{~K}}\) and \(\mathrm{101.3 \mathrm{kPa}}\)
4 \({\rm{0^\circ C}}{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} {\rm{1}}\;{\rm{atm}}{\rm{.}}\)
KCET - 2007
CHXI06:THERMODYNAMICS

369522 The standard enthalpy of formation \(\mathrm{\left(\Delta_{f} H_{298}^{o}\right)}\) for methane, \(\mathrm{\mathrm{CH}_{4}}\) is \(\mathrm{-74.9 \mathrm{~kJ} / \mathrm{mol}^{-1}}\). In order to calculate the average energy given out in the formation of a \(\mathrm{\mathrm{C}-\mathrm{H}}\) bond from this it is necessary to know which one of the following?

1 The dissociation energy of the hydrogen molecule, \(\mathrm{\mathrm{H}_{2}}\).
2 The first four ionisation energies of carbon.
3 The dissociation energy of \(\mathrm{H_{2}}\) and enthalpy of sublimation of carbon (graphite).
4 The first four ionisation energies of carbon and electron affinity of hydrogen.
JEE - 2014
CHXI06:THERMODYNAMICS

369523 The \(\mathrm{\mathrm{H}-\mathrm{H}}\) bond energy is \({\text{430}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\) and \({\text{Cl - Cl}}\) bond energy is \(\mathrm{240 \mathrm{kJmol}^{-1} . \Delta H}\) for \(\mathrm{\mathrm{HCl}}\) is\( - \,{\rm{90}}\;{\rm{kJ}}\). The \(\mathrm{\mathrm{H}-\mathrm{Cl}}\) bond energy is about

1 \({\text{425}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
2 \({\text{213}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
3 \({\text{306}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
4 \({\text{180}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
CHXI06:THERMODYNAMICS

369524 Which of the following statement(s) is correct?

1 Mean \(\mathrm{\mathrm{C}-\mathrm{H}}\) bond enthalpies differ slightly from compound to compound, as in \(\mathrm{\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Cl}, \mathrm{CH}_{3} \mathrm{NO}_{2}}\) etc. but it does not differ in a great deal.
2 The reaction enthalpies are very important quantities as these arise from the changes that accompany the breaking of old bonds and formation of the new bonds.
3 \(\mathrm{\Delta_{\mathrm{r}} \mathrm{H}^{\circ}=\sum}\) bond enthalpies of reactants \(\mathrm{-\sum}\) bond enthalpies of products.
4 All of the above.
CHXI06:THERMODYNAMICS

369525 Enthalpy change for the reaction, \(\mathrm{4 \mathrm{H}(\mathrm{g}) \longrightarrow 2 \mathrm{H}_{2}(\mathrm{~g})}\) is \(\mathrm{-869.6 \mathrm{~kJ}}\) the dissociation energy of \(\mathrm{\mathrm{H}-\mathrm{H}}\) bond is

1 \(\mathrm{+217.4 \mathrm{~kJ}}\)
2 \(\mathrm{-434.8 \mathrm{~kJ}}\)
3 \(\mathrm{-869.6 \mathrm{~kJ}}\)
4 \(\mathrm{+434.8 \mathrm{~kJ}}\)
Join With Us for More Updates
CHXI06:THERMODYNAMICS

369468 Thermodynamic standard conditions of temperature and pressure are

1 \(\mathrm{0^{\circ} \mathrm{C}}\) and \(\mathrm{101.3 \mathrm{kPa}}\)
2 \(\mathrm{298 \mathrm{~K}}\) and \(\mathrm{1 \mathrm{~atm}}\)
3 \(\mathrm{273 \mathrm{~K}}\) and \(\mathrm{101.3 \mathrm{kPa}}\)
4 \({\rm{0^\circ C}}{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} {\rm{1}}\;{\rm{atm}}{\rm{.}}\)
KCET - 2007
CHXI06:THERMODYNAMICS

369522 The standard enthalpy of formation \(\mathrm{\left(\Delta_{f} H_{298}^{o}\right)}\) for methane, \(\mathrm{\mathrm{CH}_{4}}\) is \(\mathrm{-74.9 \mathrm{~kJ} / \mathrm{mol}^{-1}}\). In order to calculate the average energy given out in the formation of a \(\mathrm{\mathrm{C}-\mathrm{H}}\) bond from this it is necessary to know which one of the following?

1 The dissociation energy of the hydrogen molecule, \(\mathrm{\mathrm{H}_{2}}\).
2 The first four ionisation energies of carbon.
3 The dissociation energy of \(\mathrm{H_{2}}\) and enthalpy of sublimation of carbon (graphite).
4 The first four ionisation energies of carbon and electron affinity of hydrogen.
JEE - 2014
CHXI06:THERMODYNAMICS

369523 The \(\mathrm{\mathrm{H}-\mathrm{H}}\) bond energy is \({\text{430}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\) and \({\text{Cl - Cl}}\) bond energy is \(\mathrm{240 \mathrm{kJmol}^{-1} . \Delta H}\) for \(\mathrm{\mathrm{HCl}}\) is\( - \,{\rm{90}}\;{\rm{kJ}}\). The \(\mathrm{\mathrm{H}-\mathrm{Cl}}\) bond energy is about

1 \({\text{425}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
2 \({\text{213}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
3 \({\text{306}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
4 \({\text{180}}\,{\text{k}}\,{\text{J}}\,{\text{mo}}{{\text{l}}^{{\text{ - 1}}}}\)
CHXI06:THERMODYNAMICS

369524 Which of the following statement(s) is correct?

1 Mean \(\mathrm{\mathrm{C}-\mathrm{H}}\) bond enthalpies differ slightly from compound to compound, as in \(\mathrm{\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Cl}, \mathrm{CH}_{3} \mathrm{NO}_{2}}\) etc. but it does not differ in a great deal.
2 The reaction enthalpies are very important quantities as these arise from the changes that accompany the breaking of old bonds and formation of the new bonds.
3 \(\mathrm{\Delta_{\mathrm{r}} \mathrm{H}^{\circ}=\sum}\) bond enthalpies of reactants \(\mathrm{-\sum}\) bond enthalpies of products.
4 All of the above.
CHXI06:THERMODYNAMICS

369525 Enthalpy change for the reaction, \(\mathrm{4 \mathrm{H}(\mathrm{g}) \longrightarrow 2 \mathrm{H}_{2}(\mathrm{~g})}\) is \(\mathrm{-869.6 \mathrm{~kJ}}\) the dissociation energy of \(\mathrm{\mathrm{H}-\mathrm{H}}\) bond is

1 \(\mathrm{+217.4 \mathrm{~kJ}}\)
2 \(\mathrm{-434.8 \mathrm{~kJ}}\)
3 \(\mathrm{-869.6 \mathrm{~kJ}}\)
4 \(\mathrm{+434.8 \mathrm{~kJ}}\)