(D) The given equations are:$(i) \ Zn + \frac{1}{2}O_2 \rightarrow ZnO; \ \Delta H_1 = -84000 \ cal$$(ii) \ Hg + \frac{1}{2}O_2 \rightarrow HgO; \ \De

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

(D) The given equations are:$(i) \ Zn + \frac{1}{2}O_2 \rightarrow ZnO; \ \Delta H_1 = -84000 \ cal$$(ii) \ Hg + \frac{1}{2}O_2 \rightarrow HgO; \ \Delta H_2 = -21700 \ cal$We need to find $\Delta H$ for the reaction:$(iii) \ Zn + HgO \rightarrow ZnO + Hg$Applying Hess's Law,we can obtain equation $(iii)$ by subtracting equation $(ii)$ from equation $(i)$:$(iii) = (i) - (ii)$$\Delta H = \Delta H_1 - \Delta H_2$$\Delta H = -84000 - (-21700)$$\Delta H = -84000 + 21700 = -62300 \ cal$

Class 11 Chemistry Thermodynamics Heat of reaction, Bond energy and Hess law

Medium

Given the following thermochemical equations:
$(i) \ Zn + \frac{1}{2}O_2 \rightarrow ZnO + 84000 \ cal$
$(ii) \ Hg + \frac{1}{2}O_2 \rightarrow HgO + 21700 \ cal$
Calculate the heat of reaction $(\Delta H)$ for the reaction: $Zn + HgO \rightarrow ZnO + Hg$. (in $cal$)

A
$105700$
B
$62300$
C
$-105700$
D
$-62300$

Explore More

Browse All

Question Bank

All Subjects

Class 11 Questions

Class 11

Chemistry Questions

Chapter

Thermodynamics

Subtopic

Heat of reaction, Bond energy and Hess law

The enthalpy change $(\Delta H)$ for the process $N_2H_{4(g)} \to 2N_{(g)} + 4H_{(g)}$ is $1724 \ kJ \ mol^{-1}$. If the bond energy of $N-H$ bond in ammonia is $391 \ kJ \ mol^{-1}$,what is the bond energy of $N-N$ bond in $N_2H_4$ in $kJ \ mol^{-1}$?

Medium

View Solution

Consider the following data:
$\Delta_{f}H^{\Theta}(CH_{4}, g) = -X \ kJ \ mol^{-1}$
Enthalpy of sublimation of graphite = $Y \ kJ \ mol^{-1}$
Dissociation enthalpy of $H_{2} = Z \ kJ \ mol^{-1}$
The bond enthalpy of $C-H$ bond is given by:

DifficultJEE MAIN 2026

View Solution

When $0.5 \ mol$ of $HNO_3$ reacts with $0.2 \ mol$ of $KOH$,the heat of neutralization is equal to ...... $kJ$.

Medium

View Solution

$AB$,$A_2$ and $B_2$ are diatomic molecules. If the bond enthalpies of $A_2$,$AB$ and $B_2$ are in the ratio $1:1:0.5$ and enthalpy of formation of $AB$ from $A_2$ and $B_2$ is $-100 \, kJ \, mol^{-1}$,what is the bond energy of $A_2$ in $kJ \, mol^{-1}$?

DifficultAIIMS 2012

View Solution

The heat of formation of $H_2O$ is $-286 \, kJ/mol$ and $H_2O_2$ is $-188 \, kJ/mol$. The enthalpy change for the reaction $2H_2O_2 \to 2H_2O + O_2$ is......$kJ$.

Medium

View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial

For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free

For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo

Given the following thermochemical equations:$(i) \ Zn + \frac{1}{2}O_2 \rightarrow ZnO + 84000 \ cal$$(ii) \ Hg + \frac{1}{2}O_2 \rightarrow HgO + 21700 \ cal$Calculate the heat of reaction $(\Delta H)$ for the reaction: $Zn + HgO \rightarrow ZnO + Hg$. (in $cal$)

Similar Questions

The enthalpy change $(\Delta H)$ for the process $N_2H_{4(g)} \to 2N_{(g)} + 4H_{(g)}$ is $1724 \ kJ \ mol^{-1}$. If the bond energy of $N-H$ bond in ammonia is $391 \ kJ \ mol^{-1}$,what is the bond energy of $N-N$ bond in $N_2H_4$ in $kJ \ mol^{-1}$?

Consider the following data:$\Delta_{f}H^{\Theta}(CH_{4}, g) = -X \ kJ \ mol^{-1}$Enthalpy of sublimation of graphite = $Y \ kJ \ mol^{-1}$Dissociation enthalpy of $H_{2} = Z \ kJ \ mol^{-1}$The bond enthalpy of $C-H$ bond is given by:

When $0.5 \ mol$ of $HNO_3$ reacts with $0.2 \ mol$ of $KOH$,the heat of neutralization is equal to ...... $kJ$.

$AB$,$A_2$ and $B_2$ are diatomic molecules. If the bond enthalpies of $A_2$,$AB$ and $B_2$ are in the ratio $1:1:0.5$ and enthalpy of formation of $AB$ from $A_2$ and $B_2$ is $-100 \, kJ \, mol^{-1}$,what is the bond energy of $A_2$ in $kJ \, mol^{-1}$?

The heat of formation of $H_2O$ is $-286 \, kJ/mol$ and $H_2O_2$ is $-188 \, kJ/mol$. The enthalpy change for the reaction $2H_2O_2 \to 2H_2O + O_2$ is......$kJ$.

Vedclass Test Series

Exam Paper Generator

Online Exam Module

Given the following thermochemical equations:
$(i) \ Zn + \frac{1}{2}O_2 \rightarrow ZnO + 84000 \ cal$
$(ii) \ Hg + \frac{1}{2}O_2 \rightarrow HgO + 21700 \ cal$
Calculate the heat of reaction $(\Delta H)$ for the reaction: $Zn + HgO \rightarrow ZnO + Hg$. (in $cal$)

Consider the following data:
$\Delta_{f}H^{\Theta}(CH_{4}, g) = -X \ kJ \ mol^{-1}$
Enthalpy of sublimation of graphite = $Y \ kJ \ mol^{-1}$
Dissociation enthalpy of $H_{2} = Z \ kJ \ mol^{-1}$
The bond enthalpy of $C-H$ bond is given by: