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JEE Main 26 July 2022, Shift 2, Chemistry Q83

Question 83 of 90 in this shift, Chemistry question 23 of 30, Section B.

For the reaction H2F2(g)→H2(g)+F2(g)\mathrm{H_2F_2(g) \rightarrow H_2(g) + F_2(g)} ΔU\Delta U = −59.6 kJ mol−1\mathrm{mol^{-1}} at 27°C. The enthalpy change for the above reaction is (−) ________ kJ mol−1\mathrm{mol^{-1}} [nearest integer] Given: R = 8.314 J K−1mol−1\mathrm{K^{-1}mol^{-1}}.

Official answer

57

NTA final key.

Same idea in other shifts

Asked 10× in all
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  6. 29 Jun 2022, Shift 2 · Q822.2 g of nitrous oxide (N2O\mathrm{N_2O}) gas is cooled at a constant pressure of 1 atm from 310 K to 270 K causing the compression of the…MediumNumerical value
  7. 26 Aug 2021, Shift 2 · Q53For water ΔvapH\Delta_{\mathrm{vap}}H = 41 kJ mol−1\mathrm{mol^{-1}} at 373 K and 1 bar pressure. Assuming that water vapour is an ideal gas…MediumNumerical value
  8. 2 Sep 2020, Shift 1 · Q46The internal energy change (in J) when 90 g of water undergoes complete evaporation at 100∘100^\circC is ______. (Given : ΔHvap\Delta H_{vap}…EasyNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.