(A) The formation reaction of $CH_4$ is: $C_{(s)} + 2H_{2(g)} \to CH_{4(g)}$.We are given:$(i)$ $C_{(s)} + O_{2(g)} \to CO_{2(g)}, \Delta H_1 = -394 \

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(A) The formation reaction of $CH_4$ is: $C_{(s)} + 2H_{2(g)} \to CH_{4(g)}$.We are given:$(i)$ $C_{(s)} + O_{2(g)} \to CO_{2(g)}, \Delta H_1 = -394 \ kJ$$(ii)$ $2H_{2(g)} + O_{2(g)} \to 2H_2O_{(l)}, \Delta H_2 = -568 \ kJ$$(iii)$ $CH_{4(g)} + 2O_{2(g)} \to CO_{2(g)} + 2H_2O_{(l)}, \Delta H_3 = -892 \ kJ$To obtain the formation reaction,perform $(i)$ + $(ii)$ - $(iii)$:$\Delta H_f = \Delta H_1 + \Delta H_2 - \Delta H_3$$\Delta H_f = -394 + (-568) - (-892)$$\Delta H_f = -394 - 568 + 892$$\Delta H_f = -962 + 892 = -70 \ kJ$.

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

Medium

Given that:
$C_{(s)} + O_{2(g)} \to CO_{2(g)}, \Delta H = -394 \ kJ$
$2H_{2(g)} + O_{2(g)} \to 2H_2O_{(l)}, \Delta H = -568 \ kJ$
$CH_{4(g)} + 2O_{2(g)} \to CO_{2(g)} + 2H_2O_{(l)}, \Delta H = -892 \ kJ$
Calculate the heat of formation of $CH_{4(g)}$ in $kJ$.

A
$-70$
B
$71.8$
C
$-76$
D
$+782$

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Class 11

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Thermodynamics

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Heat of reaction, Bond energy and Hess law

The heat of formation of methane $C_{(s)} + 2H_{2(g)} \to CH_{4(g)}$ at constant pressure is $-18500 \ cal$ at $25 \ ^oC$. The heat of reaction at constant volume would be (in $cal$)

Medium

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At $25^{\circ} C$ and $1 \ atm$ pressure,the enthalpies of combustion are as given below:

Substance $H_{2(g)}$ $C_{\text{(graphite)}}$ $C_{2}H_{6(g)}$

$\Delta_{c}H^{\Theta} / (kJ \ mol^{-1})$ $-286.0$ $-394.0$ $-1560.0$

The enthalpy of formation of ethane is ........ .

MediumJEE MAIN 2022

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Which of the following substances has the highest value of standard molar enthalpy of formation at $298 \ K$?

MediumAP EAMCET 2020

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What is the enthalpy of formation of $NH_3$ if the bond enthalpies are $(N \equiv N) = 941 \ kJ/mol$,$(H-H) = 436 \ kJ/mol$,and $(N-H) = 389 \ kJ/mol$?

EasyMHT CET 2021

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Consider the reactions:
$C_{(s)} + 2H_{2(g)} \to CH_{4(g)}, \Delta H = -x \ kcal$
$C_{(g)} + 4H_{(g)} \to CH_{4(g)}, \Delta H = -x_1 \ kcal$
$CH_{4(g)} \to CH_{3(g)} + H_{(g)}, \Delta H = +y \ kcal$
The bond energy of $C-H$ bond is:

Medium

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Substance	$H_{2(g)}$	$C_{\text{(graphite)}}$	$C_{2}H_{6(g)}$
$\Delta_{c}H^{\Theta} / (kJ \ mol^{-1})$	$-286.0$	$-394.0$	$-1560.0$

Given that:$C_{(s)} + O_{2(g)} \to CO_{2(g)}, \Delta H = -394 \ kJ$$2H_{2(g)} + O_{2(g)} \to 2H_2O_{(l)}, \Delta H = -568 \ kJ$$CH_{4(g)} + 2O_{2(g)} \to CO_{2(g)} + 2H_2O_{(l)}, \Delta H = -892 \ kJ$Calculate the heat of formation of $CH_{4(g)}$ in $kJ$.

Similar Questions

The heat of formation of methane $C_{(s)} + 2H_{2(g)} \to CH_{4(g)}$ at constant pressure is $-18500 \ cal$ at $25 \ ^oC$. The heat of reaction at constant volume would be (in $cal$)

At $25^{\circ} C$ and $1 \ atm$ pressure,the enthalpies of combustion are as given below: Substance $H_{2(g)}$ $C_{\text{(graphite)}}$ $C_{2}H_{6(g)}$ $\Delta_{c}H^{\Theta} / (kJ \ mol^{-1})$ $-286.0$ $-394.0$ $-1560.0$ The enthalpy of formation of ethane is ........ .

Which of the following substances has the highest value of standard molar enthalpy of formation at $298 \ K$?

What is the enthalpy of formation of $NH_3$ if the bond enthalpies are $(N \equiv N) = 941 \ kJ/mol$,$(H-H) = 436 \ kJ/mol$,and $(N-H) = 389 \ kJ/mol$?

Consider the reactions:$C_{(s)} + 2H_{2(g)} \to CH_{4(g)}, \Delta H = -x \ kcal$$C_{(g)} + 4H_{(g)} \to CH_{4(g)}, \Delta H = -x_1 \ kcal$$CH_{4(g)} \to CH_{3(g)} + H_{(g)}, \Delta H = +y \ kcal$The bond energy of $C-H$ bond is:

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Given that:
$C_{(s)} + O_{2(g)} \to CO_{2(g)}, \Delta H = -394 \ kJ$
$2H_{2(g)} + O_{2(g)} \to 2H_2O_{(l)}, \Delta H = -568 \ kJ$
$CH_{4(g)} + 2O_{2(g)} \to CO_{2(g)} + 2H_2O_{(l)}, \Delta H = -892 \ kJ$
Calculate the heat of formation of $CH_{4(g)}$ in $kJ$.

At $25^{\circ} C$ and $1 \ atm$ pressure,the enthalpies of combustion are as given below:

Substance $H_{2(g)}$ $C_{\text{(graphite)}}$ $C_{2}H_{6(g)}$

$\Delta_{c}H^{\Theta} / (kJ \ mol^{-1})$ $-286.0$ $-394.0$ $-1560.0$

The enthalpy of formation of ethane is ........ .

Consider the reactions:
$C_{(s)} + 2H_{2(g)} \to CH_{4(g)}, \Delta H = -x \ kcal$
$C_{(g)} + 4H_{(g)} \to CH_{4(g)}, \Delta H = -x_1 \ kcal$
$CH_{4(g)} \to CH_{3(g)} + H_{(g)}, \Delta H = +y \ kcal$
The bond energy of $C-H$ bond is: