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Friday, 9 October

JEE Main 2017 · ChemistryMultiple choiceSingle correctEasyCalculation

JEE Main 2 April 2017 (offline), Chemistry Q31

Question 31 of 90 in this shift, Chemistry question 1 of 30.

Given C(graphite)+O2(g)→CO2(g)\mathrm{C_{(graphite)}+O_2(g)\rightarrow CO_2(g)} ; ΔrH∘=−393.5 kJ mol−1\Delta_rH^\circ=-393.5\ \mathrm{kJ\,mol^{-1}} H2(g)+12O2(g)→H2O(l)\mathrm{H_2(g)+\frac{1}{2}O_2(g)\rightarrow H_2O(l)} ; ΔrH∘=−285.8 kJ mol−1\Delta_rH^\circ=-285.8\ \mathrm{kJ\,mol^{-1}} CO2(g)+2H2O(l)→CH4(g)+2O2(g)\mathrm{CO_2(g)+2H_2O(l)\rightarrow CH_4(g)+2O_2(g)} ; ΔrH∘=+890.3 kJ mol−1\Delta_rH^\circ=+890.3\ \mathrm{kJ\,mol^{-1}} Based on the above thermochemical equations, the value of ΔrH∘\Delta_rH^\circ at 298 K for the reaction C(graphite)+2H2(g)→CH4(g)\mathrm{C_{(graphite)}+2H_2(g)\rightarrow CH_4(g)} will be :
  1. (1)−74.8 kJ mol−1-74.8\ \mathrm{kJ\,mol^{-1}}Official answer
  2. (2)−144.0 kJ mol−1-144.0\ \mathrm{kJ\,mol^{-1}}
  3. (3)+74.8 kJ mol−1+74.8\ \mathrm{kJ\,mol^{-1}}
  4. (4)+144.0 kJ mol−1+144.0\ \mathrm{kJ\,mol^{-1}}

Official answer

Option 1

CBSE answer key (25/04/2017, used for result).

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