Home
Class 11
CHEMISTRY
The standard enthalpy of formation of hy...

The standard enthalpy of formation of hypothetical MgCl is `-125kJ mol^(-1)` and for `MgCl_(2)` is -642 kJ `mol^(-1)`. What is the enthalpy of the disproportionation of MgCl ?

A

`-492 kJ mol^(-1)`

B

`-392 kJ mol^(-1)`

C

`-767kJ mol^(-1)`

D

`-517 kJ mol^(-1)`

Text Solution

Verified by Experts

The correct Answer is:
B
(i) `Mg_((s)) + Cl_(2(g)) rarr MgCl_(2(s)) , Detlta H_(1) = - 642`
(ii) `Mg_((s)) + 1//2Cl_(2(g)) rarr MgCl_((s)) , Delta H_(2) = - 125`
(iii) `2MgCl rarr MgCl_(2) + Mg, Delta H`= ?
`Delta H = Delta H_(1) - Delta H_(2) = - 392 kJ mol^(-1)`
Promotional Banner

Topper's Solved these Questions

  • CHEMICAL THERMODYNAMICS

    AAKASH SERIES|Exercise ADDITIONAL PRACTICE EXERCISE (LEVEL - II LECTURE SHEET (ADVANCED) STRAIGHT OBJECTIVE TYPE QUESTIONS)|8 Videos

  • CHEMICAL THERMODYNAMICS

    AAKASH SERIES|Exercise ADDITIONAL PRACTICE EXERCISE (LEVEL - II LECTURE SHEET (ADVANCED) MORE THAN ONE CORRECT ANSWER TYPE QUESTIONS)|7 Videos

  • CHEMICAL THERMODYNAMICS

    AAKASH SERIES|Exercise PRACTICE SHEET (EXERCISE- III) (LEVEL- II (ADVANCED) (INTEGER TYPE QUESTIONS)|5 Videos

  • CHEMICAL THERMODYANMICS

    AAKASH SERIES|Exercise Questions For Descriptive Answers|28 Videos

  • ELECTRON MIGRATION EFFECTS

    AAKASH SERIES|Exercise QUESTIONS FOR DESCRIPTIVE ANSWERS|10 Videos

Similar Questions

Explore conceptually related problems

If the standard molar enthalpy of formation of SO _(2 (g)) and SO _(3(g)) is - 296 . 82 kJ mol ^(-1) and -395 . 72 kJ mol ^(-1) respectively, then enthalpy change for the reaction in kJ mol ^(-1) , SO _(2 (g)) + (1)/(2) O _(2 (g)) to SO _(3(g)) , is

The standard enthalpies of formation of CO_(2) gas and HCOOH_((l)) are -393.7 kJ mol^(-1) and -409.2 kJ mol^(-1) respectively. Which of the following are correct?

The standard molar enthalpies of formation of cyclohexane (l) and benzene (l) at 25^(@)C "are" -156 and +49kJ mol^(-1) respectively. The standard enthalpy of hydrogenation of cyclohexene (l) at 25^(@)C is -119kJ mol^(-1) . Use these data to estimate the magnitude of the resonance energy of benzene.

If the activation energy for the forward reaction is 150kJ mol^(-1) and that of the reverse reaction is 260kJ mol^(-1) . What is the enthalpy change for the reaction

Calculate the lattice enthalpy of calcium oxide from the following data. Data found in the IB chemistry data booklet and the Born Haber cycle drawn in part (a) enthalpy of atomisation of Ca_((s)) = + 178kJ mol^(-1) second ionization energy of Ca_((g))= +1150 kJ mol^(-1) enthalpy of formation of calcium oxide = -635 kJ mol^(-1 )

The enthalpies of combustion of carbon and carbon monoxide are -390 KJ mol^(-1) and -278 KJ mol^(-1) respectively. The enthalpy of formation of carbon monoxide is

The standard enthalpy of formation (Delta H^(0)) at 298K for methane, CH_(4(g)) is 74.8 kJ mol^(1) . The additional information required to determine the average energy for C-H bond formation would be