Given the thermochemical equations and their corresponding enthalpies:
CH₄ (g) + 2 O₂(g) CO₂ (g) + 2 H₂ O ( ) D H = - 890 kJ C₂ H₄ (g) + 3 O₂(g) 2 CO₂ (g) + 2 H₂ O ( ) D H = - 1410 kJ What is the D H for the following reaction?
2 CH₄ (g) + O₂(g) C₂ H₄ (g) + 2 H₂ O ( )

Question

Given the thermochemical equations and their corresponding enthalpies:
CH₄ (g) + 2 O₂(g) CO₂ (g) + 2 H₂ O (

Given the thermochemical equations and their corresponding enthalpies: CH<sub>4</sub> (g) + 2 O₂(g) CO₂ (g) + 2 H₂ O ( ) D H = - 890 kJ C₂ H<sub>4</sub> (g) + 3 O₂(g) 2 CO₂ (g) + 2 H₂ O ( ) D H = - 1410 kJ What is the D H for the following reaction? 2 CH<sub>4</sub> (g) + O₂(g) C₂ H<sub>4</sub> (g) + 2 H₂ O ( ) A) 3190 kJ B) - 2300 kJ C) - 520 kJ D) - 370 kJ E) none of these

) D H = - 890 kJ C₂ H₄ (g) + 3 O₂(g) 2 CO₂ (g) + 2 H₂ O ( Given the thermochemical equations and their corresponding enthalpies: CH4 (g) + 2 O₂(g) CO₂ (g) + 2 H₂ O ( ) D H = - 890 kJ C₂ H4 (g) + 3 O₂(g) 2 CO₂ (g) + 2 H₂ O ( ) D H = - 1410 kJ What is the D H for the following reaction? 2 CH4 (g) + O₂(g) C₂ H4 (g) + 2 H₂ O ( ) A) 3190 kJ B) - 2300 kJ C) - 520 kJ D) - 370 kJ E) none of these

) D H = - 1410 kJ What is the D H for the following reaction?
2 CH₄ (g) + O₂(g) C₂ H₄ (g) + 2 H₂ O ( Given the thermochemical equations and their corresponding enthalpies: CH4 (g) + 2 O₂(g) CO₂ (g) + 2 H₂ O ( ) D H = - 890 kJ C₂ H4 (g) + 3 O₂(g) 2 CO₂ (g) + 2 H₂ O ( ) D H = - 1410 kJ What is the D H for the following reaction? 2 CH4 (g) + O₂(g) C₂ H4 (g) + 2 H₂ O ( ) A) 3190 kJ B) - 2300 kJ C) - 520 kJ D) - 370 kJ E) none of these

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Quizplus · Accepted Answer

To find D H for the given reaction, we need to manipulate the given thermochemical equations in such a way that the reactants and products of the desired reaction are present in the same amount as on the left and right sides of the equation, respectively. We can achieve this by reversing the first equation and multiplying the second equation by two: 2 C₂ H₄ (g) + 4 O₂(g) 2 CO₂ (g) + 4 H₂ O D H = 2 × (-890 kJ) = - 1780 kJ 4 CH₄ (g) + 6 O₂(g) 4 CO₂ (g) + 4 H₂ O D H = 2 × (-1410 kJ) = - 2820 kJ Now, we can add these two equations and cancel out the common species on the left and right sides: 2 C₂ H₄ (g) + 5 O₂(g) 3 CO₂ (g) + 6 H₂ O D H = - 4600 kJ Finally, we can subtract the first equation from this new equation to obtain the desired reaction: 2 CH₄ (g) + O₂(g) C₂ H₄ (g) + 2 H₂ O D H = (-4600 kJ) - (-1780 kJ) = - 2820 kJ However, the question is asking for the magnitude of D H, which is 2820 kJ. Since the reaction is exothermic, the sign of D H is negative. Option D is the only choice with the correct magnitude and sign.

Given the Thermochemical Equations and Their Corresponding Enthalpies