PYQs Homework Notes Mocks Board Daily Homework MHT-CET Chemistry Question type Standard enthalpy of reaction from standard enthalpies of formation This type of question, asked 9 times: 20 Apr 2025 S2, 21 Apr 2025 S2, 22 Apr 2025 S1, 23 Apr 2025 S1, 26 Apr 2025 S2, 17 Apr 2026 S2, 18 Apr 2026 S2, 15 May 2026 S2, 19 May 2026 S2. All 9 questions below, oldest first.
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Question 1 20 Apr 2025 S2
100 Calculate the standard enthalpy change of following reaction. C 2 H 4 ( g ) + 3 O 2 ( g ) ⟶ 2 C O 2 ( g ) + 2 H 2 O ( l ) − C_{2}H_{4(\text{ }g)}+ 3O_{2(\text{ }g)}\longrightarrow 2CO_{2(\text{ }g)}+ 2H_{2}O_{(l)}- C 2 H 4 ( g ) + 3 O 2 ( g ) ⟶ 2 C O 2 ( g ) + 2 H 2 O ( l ) − If Δ f H ∘ ( C 2 H 4 ) = − 52 k J m o l − 1 \Delta_{f}H^{\circ}\left( C_{2}H_{4} \right)= - 52\text{ }kJ{\text{ }mol}^{- 1} Δ f H ∘ ( C 2 H 4 ) = − 52 k J m o l − 1
Δ f H ∘ ( C O 2 ) = − 390 k J m o l − 1 Δ f H ∘ ( H 2 O ) = − 286 k J m o l − 1 \begin{gathered}\Delta_{f}H^{\circ}\left( CO_{2} \right)= - 390\text{ }kJ{\text{ }mol}^{- 1} \\ \Delta_{f}H^{\circ}\left( H_{2}O \right)= - 286\text{ }kJ{\text{ }mol}^{- 1}\end{gathered} Δ f H ∘ ( C O 2 ) = − 390 k J m o l − 1 Δ f H ∘ ( H 2 O ) = − 286 k J m o l − 1 A. -650 Kj
B. -1300 kJ
C. -1950 kJ
D. -1500 kJ
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Question 2 21 Apr 2025 S2
56 Calculate standard enthalpy change of reaction
C 2 H 2 ( g ) + 5 2 O 2 ( g ) ⟶ 2 C O 2 ( g ) + H 2 O ( l ) C_{2}H_{2(\text{ }g)}+\frac{5}{2}O_{2(\text{ }g)}\longrightarrow 2CO_{2(\text{ }g)}+H_{2}O_{(l)} C 2 H 2 ( g ) + 2 5 O 2 ( g ) ⟶ 2 C O 2 ( g ) + H 2 O ( l ) , if
Δ f H ∘ ( C O 2 ) = − 393 k J m o l − 1 Δ f H ∘ ( H 2 O ) = − 286 k J m o l − 1 Δ f H ∘ ( C 2 H 2 ) = 227 k J m o l − 1 \begin{gathered}\Delta_{f}H^{\circ}\left( CO_{2} \right)= - 393\text{ }kJ{\text{ }mol}^{- 1} \\ \Delta_{f}H^{\circ}\left( H_{2}O \right)= - 286\text{ }kJ{\text{ }mol}^{- 1} \\ \Delta_{f}H^{\circ}\left( C_{2}H_{2} \right)= 227\text{ }kJ{\text{ }mol}^{- 1}\end{gathered} Δ f H ∘ ( C O 2 ) = − 393 k J m o l − 1 Δ f H ∘ ( H 2 O ) = − 286 k J m o l − 1 Δ f H ∘ ( C 2 H 2 ) = 227 k J m o l − 1 A. -650 kJ
B. -1950 kJ
C. -1299 kJ
D. -2598 kJ
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Question 3 22 Apr 2025 S1
96 Calculate the standard enthalpy change of following reaction
C H 4 ( g ) + 2 O 2 ( g ) → C O 2 ( g ) + 2 H 2 O ( l ) CH_{4(\text{ }g)}+ 2O_{2(\text{ }g)}\rightarrow CO_{2(\text{ }g)}+ 2H_{2}O_{(\mathcal{l})} C H 4 ( g ) + 2 O 2 ( g ) → C O 2 ( g ) + 2 H 2 O ( l ) If Δ f H ∘ ( C H 4 ) = − 75 k J m o l − 1 \Delta_{f}H^{\circ}\left( CH_{4} \right)= - 75\text{ }kJ{\text{ }mol}^{- 1} Δ f H ∘ ( C H 4 ) = − 75 k J m o l − 1
Δ f H ∘ ( C O 2 ) = − 394 k J m o l − 1 Δ f H ∘ ( H 2 O ) = − 286 k J m o l − 1 \begin{gathered}\Delta_{f}H^{\circ}\left( CO_{2} \right)= - 394\text{ }kJ{\text{ }mol}^{- 1} \\ \Delta_{f}H^{\circ}\left( H_{2}O \right)= - 286\text{ }kJ{\text{ }mol}^{- 1}\end{gathered} Δ f H ∘ ( C O 2 ) = − 394 k J m o l − 1 Δ f H ∘ ( H 2 O ) = − 286 k J m o l − 1 A. -891 kJ
B. − 1041 k J \ - 1041\text{ }kJ − 1041 k J C. -966 kJ
D. -1782 kJ
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Question 4 23 Apr 2025 S1
74 Calculate the standard enthalpy change for reaction,
C 2 H 5 O H ( l ) + 3 O 2 ( g ) ⟶ 2 C O 2 ( g ) + 3 H 2 O ( l ) C_{2}H_{5}OH_{(l)}+ 3O_{2(\text{ }g)}\longrightarrow 2CO_{2(\text{ }g)}+ 3H_{2}O_{(l)} C 2 H 5 O H ( l ) + 3 O 2 ( g ) ⟶ 2 C O 2 ( g ) + 3 H 2 O ( l ) if Δ f H ∘ ( C 2 H 5 O H ) = − 280 k J m o l − 1 \Delta_{f}H^{\circ}\left( C_{2}H_{5}OH \right)= - 280\text{ }kJ{\text{ }mol}^{- 1} Δ f H ∘ ( C 2 H 5 O H ) = − 280 k J m o l − 1
Δ f H ∘ ( C O 2 ) = − 390 k J m o l − 1 Δ f H H ∘ ( H 2 O ) = − 285 k J m o l − 1 \begin{gathered}\Delta_{f}H^{\circ}\left( CO_{2} \right)= - 390\text{ }kJ{\text{ }mol}^{- 1} \\ \Delta_{fH}H^{\circ}\left( H_{2}O \right)= - 285\text{ }kJ{\text{ }mol}^{- 1}\end{gathered} Δ f H ∘ ( C O 2 ) = − 390 k J m o l − 1 Δ f H H ∘ ( H 2 O ) = − 285 k J m o l − 1 A. -678.00 kJ
B. -2033.00 kJ
C. -1355.00 kJ
D. -1016.00 Kj
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Question 5 26 Apr 2025 S2
75 Calculate the standard enthalpy change of following reaction.
C H 4 ( g ) + 2 O 2 ( g ) → C O 2 ( g ) + 2 H 2 O ( l ) CH_{4(\text{ }g)}+ 2O_{2(\text{ }g)}\rightarrow CO_{2(\text{ }g)}+ 2H_{2}O_{(\mathcal{l})} C H 4 ( g ) + 2 O 2 ( g ) → C O 2 ( g ) + 2 H 2 O ( l ) if Δ t H ∘ ( C H 4 ) = − 75 k J m o l − 1 \Delta_{t}H^{\circ}\left( CH_{4} \right)= - 75\text{ }kJ{\text{ }mol}^{- 1} Δ t H ∘ ( C H 4 ) = − 75 k J m o l − 1
Δ t H ∘ ( C O 2 ) = − 390 k J m o l − 1 Δ r H ∘ ( H 2 O ) = − 286 k J m o l − 1 \begin{gathered}\Delta_{t}H^{\circ}\left( CO_{2} \right)= - 390\text{ }kJ{\text{ }mol}^{- 1} \\ \Delta_{r}H^{\circ}\left( H_{2}O \right)= - 286\text{ }kJ{\text{ }mol}^{- 1}\end{gathered} Δ t H ∘ ( C O 2 ) = − 390 k J m o l − 1 Δ r H ∘ ( H 2 O ) = − 286 k J m o l − 1 A. -887.00 kJ
B. -1325.00 kJ
C. -1035.00 kJ
D. − 1770.00 k J \ - 1770.00\text{ }kJ − 1770.00 k J Tap an option to check your answer.
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Question 6 17 Apr 2026 S2
7 Calculate the standard enthalpy of combustion of carbon monoxide if
Δ f H ∘ ( C O ) = − 110 k J m o l − 1 \Delta_f H^\circ(\mathrm{CO}) = -110\ \mathrm{kJ\,mol^{-1}} Δ f H ∘ ( CO ) = − 110 kJ mo l − 1
Δ f H ∘ ( C O 2 ) = − 393 k J m o l − 1 \Delta_f H^\circ(\mathrm{CO_2}) = -393\ \mathrm{kJ\,mol^{-1}} Δ f H ∘ ( C O 2 ) = − 393 kJ mo l − 1 A. − 503 k J m o l − 1 -503\ \mathrm{kJ\,mol^{-1}} − 503 kJ mo l − 1 B. − 110 k J m o l − 1 -110\ \mathrm{kJ\,mol^{-1}} − 110 kJ mo l − 1 C. − 283 k J m o l − 1 -283\ \mathrm{kJ\,mol^{-1}} − 283 kJ mo l − 1 D. − 383 k J m o l − 1 -383\ \mathrm{kJ\,mol^{-1}} − 383 kJ mo l − 1 Tap an option to check your answer.
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Question 7 18 Apr 2026 S2
9 Calculate the standard enthalpy change for the following reaction,
2 C 2 H 6 ( g ) + 7 O 2 ( g ) ⟶ 4 C O 2 ( g ) + 6 H 2 O ( l ) \mathrm{2C_2H_6(g) + 7O_2(g) \longrightarrow 4CO_2(g) + 6H_2O(l)} 2 C 2 H 6 ( g ) + 7 O 2 ( g ) ⟶ 4C O 2 ( g ) + 6 H 2 O ( l )
Given, Δ f H ∘ ( C 2 H 6 ) = − 85 k J m o l − 1 \Delta_f H^\circ(\mathrm{C_2H_6}) = -85\ \mathrm{kJ\,mol^{-1}} Δ f H ∘ ( C 2 H 6 ) = − 85 kJ mo l − 1
Δ f H ∘ ( C O 2 ) = − 390 k J m o l − 1 \Delta_f H^\circ(\mathrm{CO_2}) = -390\ \mathrm{kJ\,mol^{-1}} Δ f H ∘ ( C O 2 ) = − 390 kJ mo l − 1
Δ f H ∘ ( H 2 O ) = − 285 k J m o l − 1 \Delta_f H^\circ(\mathrm{H_2O}) = -285\ \mathrm{kJ\,mol^{-1}} Δ f H ∘ ( H 2 O ) = − 285 kJ mo l − 1 A. − 2900 k J -2900\ \mathrm{kJ} − 2900 kJ B. − 3100 k J -3100\ \mathrm{kJ} − 3100 kJ C. − 3000 k J -3000\ \mathrm{kJ} − 3000 kJ D. − 3200 k J -3200\ \mathrm{kJ} − 3200 kJ Tap an option to check your answer.
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Question 8 15 May 2026 S2
6 Calculate the standard enthalpy of combustion of C 2 H 2 ( g ) \mathrm{C_2H_2}(g) C 2 H 2 ( g ) ,
C 2 H 2 ( g ) + 5 / 2 O 2 ( g ) → 2 C O 2 ( g ) + H 2 O ( l ) \mathrm{C_2H_2}(g) + 5/2\,\mathrm{O_2}(g) \rightarrow 2\mathrm{CO_2}(g) + \mathrm{H_2O}(l) C 2 H 2 ( g ) + 5/2 O 2 ( g ) → 2 C O 2 ( g ) + H 2 O ( l )
[ Δ f H 0 ( C O 2 ) = − 390 k J m o l − 1 [\Delta_f H^0(\mathrm{CO_2}) = -390\ \mathrm{kJ\ mol^{-1}} [ Δ f H 0 ( C O 2 ) = − 390 kJ mo l − 1 , Δ f H 0 ( H 2 O ) = − 285 k J m o l − 1 \Delta_f H^0(\mathrm{H_2O}) = -285\ \mathrm{kJ\ mol^{-1}} Δ f H 0 ( H 2 O ) = − 285 kJ mo l − 1 and Δ f H 0 ( C 2 H 2 ) = 225 k J m o l − 1 ] \Delta_f H^0(\mathrm{C_2H_2}) = 225\ \mathrm{kJ\ mol^{-1}}] Δ f H 0 ( C 2 H 2 ) = 225 kJ mo l − 1 ] A. Δ c H 0 ( C 2 H 2 ) = − 1290 k J m o l − 1 \Delta_c H^0(\mathrm{C_2H_2}) = -1290\ \mathrm{kJ\ mol^{-1}} Δ c H 0 ( C 2 H 2 ) = − 1290 kJ mo l − 1 B. Δ c H 0 ( C 2 H 2 ) = − 645 k J m o l − 1 \Delta_c H^0(\mathrm{C_2H_2}) = -645\ \mathrm{kJ\ mol^{-1}} Δ c H 0 ( C 2 H 2 ) = − 645 kJ mo l − 1 C. Δ c H 0 ( C 2 H 2 ) = − 1935 k J m o l − 1 \Delta_c H^0(\mathrm{C_2H_2}) = -1935\ \mathrm{kJ\ mol^{-1}} Δ c H 0 ( C 2 H 2 ) = − 1935 kJ mo l − 1 D. Δ c H 0 ( C 2 H 2 ) = − 2580 k J m o l − 1 \Delta_c H^0(\mathrm{C_2H_2}) = -2580\ \mathrm{kJ\ mol^{-1}} Δ c H 0 ( C 2 H 2 ) = − 2580 kJ mo l − 1 Tap an option to check your answer.
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Question 9 19 May 2026 S2
7 Evaluate the standard enthalpy of formation of C 2 H 4 \mathrm{C_2H_4} C 2 H 4 in kJ/mol from the following data,
C 2 H 4 ( g ) + 3 O 2 ( g ) → 2 C O 2 ( g ) + 2 H 2 O ( l ) \mathrm{C_2H_{4(g)} + 3O_{2(g)} \to 2CO_{2(g)} + 2H_2O_{(l)}} C 2 H 4 ( g ) + 3 O 2 ( g ) → 2C O 2 ( g ) + 2 H 2 O ( l ) Δ r H 0 = − 1411 \Delta_r H^0 = -1411 Δ r H 0 = − 1411 kJ/mol
Δ f H 0 ( C O 2 ) = − 393 \Delta_f H^0(\mathrm{CO_2}) = -393 Δ f H 0 ( C O 2 ) = − 393 kJ/mol
Δ f H 0 ( H 2 O ) = − 285 \Delta_f H^0(\mathrm{H_2O}) = -285 Δ f H 0 ( H 2 O ) = − 285 kJ/mol A. B. C. D. Tap an option to check your answer.
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