PYQs Homework Notes Mocks Board Daily Homework JEE Mains Chemistry Question type Combine thermochemical equations given in symbols to get the required enthalpy This type of question, asked 3 times: 10 Apr 2023, 24 Jan 2025, 29 Jan 2025. All 3 questions below, oldest first.
Try each one first, then open its answer.
Question 1 10 Apr 2023
43 Given (A) 2 C O ( g ) + O 2 ( g ) → 2 C O 2 ( g ) Δ H 1 θ = − x k J m o l − 1 2CO(g) +O_{2}(\text{ }g) \rightarrow 2CO_{2}(\text{ }g)\ \Delta H_{1}^{\theta}= - xkJmol^{- 1} 2 C O ( g ) + O 2 ( g ) → 2 C O 2 ( g ) Δ H 1 θ = − x k J m o l − 1 (B) C(graphite) + O 2 +O_{2} + O 2 (g) → C O 2 ( g ) Δ H 2 θ = − y k J m o l − 1 \rightarrow CO_{2}(\text{ }g)\Delta H_{2}^{\theta}= - ykJmol^{- 1} → C O 2 ( g ) Δ H 2 θ = − y k J m o l − 1 The Δ H θ \Delta H^{\theta} Δ H θ for the reaction C C C (graphite) + 1 2 O 2 ( g ) → C O ( g ) +\frac{1}{2}O_{2}(\text{ }g) \rightarrow CO(g) + 2 1 O 2 ( g ) → C O ( g ) is A. x − 2 y 2 \frac{x - 2y}{2} 2 x − 2 y B. x + 2 y 2 \frac{x + 2y}{2} 2 x + 2 y C. 2 x − y 2 \frac{2x - y}{2} 2 2 x − y D. Tap an option to check your answer.
Show answer
Question 2 24 Jan 2025
116 S ( g ) + 3 2 O 2 ( g ) → S O 3 ( g ) + 2 x kcal S O 2 ( g ) + 1 2 O 2 ( g ) → S O 3 ( g ) + y k c a l \begin{matrix} & S(\text{ }g) +\frac{3}{2}O_{2}(\text{ }g) \rightarrow SO_{3}(\text{ }g) + 2x\text{~kcal~} \\ & SO_{2}(\text{ }g) +\frac{1}{2}O_{2}(\text{ }g) \rightarrow SO_{3}(\text{ }g) + ykcal \end{matrix} S ( g ) + 2 3 O 2 ( g ) → S O 3 ( g ) + 2 x kcal S O 2 ( g ) + 2 1 O 2 ( g ) → S O 3 ( g ) + y k c a l The heat of formation of S O 2 ( g ) SO_{2}(\text{ }g) S O 2 ( g ) is given by : A. 2 x y k c a l \frac{2x}{y}kcal y 2 x k c a l B. y − 2 x k c a l y - 2xkcal y − 2 x k c a l C. D. Tap an option to check your answer.
Show answer
Question 3 29 Jan 2025
114 If C (diamond) → C \rightarrow C → C (graphite) + X k J m o l − 1 + XkJmol^{- 1} + X k J m o l − 1 C ( diamond ) + O 2 ( g ) → C O 2 ( g ) + Y k J m o l − 1 C ( graphite ) + O 2 ( g ) → C O 2 ( g ) + Z k J m o l − 1 \begin{matrix} & C(\text{~diamond~}) +O_{2}(\text{ }g) \rightarrow CO_{2}(\text{ }g) + Y\text{ }kJ{\text{ }mol}^{- 1} \\ & C(\text{~graphite~}) +O_{2}(\text{ }g) \rightarrow CO_{2}(\text{ }g) + Z\text{ }kJ{\text{ }mol}^{- 1} \end{matrix} C ( diamond ) + O 2 ( g ) → C O 2 ( g ) + Y k J m o l − 1 C ( graphite ) + O 2 ( g ) → C O 2 ( g ) + Z k J m o l − 1 At constant temperature. Then A. B. C. D. Tap an option to check your answer.
Show answer
