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Saturday, 31 October

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JEE Main 29 June 2022, Shift 2, Chemistry Q82

Question 82 of 90 in this shift, Chemistry question 22 of 30, Section B.

2.2 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 gas from 217.1 mL to 167.75 mL. The change in internal energy of the process, ΔU is '−x' J. The value of ‘x’ is ___. [nearest integer] (Given: atomic mass of N = 14 g mol−1\mathrm{mol^{-1}} and of O = 16 g mol−1\mathrm{mol^{-1}}. Molar heat capacity of N2O\mathrm{N_2O} is 100 J K−1\mathrm{K^{-1}}mol−1\mathrm{mol^{-1}})

Official answer

195

NTA final key.

Chapter
Thermodynamics (Chemistry)
Topic
Enthalpy and Hess's Law
Idea tested
Relation Between ΔH and ΔU

Same idea in other shifts

Asked 10× in all
  1. 8 Apr 2024, Shift 2 · Q84ΔvapH⊖\Delta_{vap}H^{\ominus} for water is +40.79 kJ mol−1+40.79\ \mathrm{kJ\,mol^{-1}} at 1 bar and 100 °C. Change in internal energy for this…EasyNumerical value
  2. 26 Jul 2022, Shift 2 · Q83For 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…EasyNumerical value
  3. 28 Jul 2022, Shift 1 · Q62Which of the following relation is not correct ?EasySingle correct
  4. 26 Jun 2022, Shift 1 · Q81For complete combustion of methanol CH3OH(l)+32O2(g)→CO2(g)+2H2O(l)\mathrm{CH_3OH(l)}+\frac{3}{2}\mathrm{O_2(g)}\rightarrow\mathrm{CO_2(g)}+2\mathrm{H_2O(l)} the…MediumNumerical value
  5. 26 Jun 2022, Shift 2 · Q84A fish swimming in water body when taken out from the water body is covered with a film of water of weight 36 g. When it is subjected to…MediumNumerical value
  6. 28 Jun 2022, Shift 2 · Q82For combustion of one mole of magnesium in an open container at 300 K and 1 bar pressure, ΔCH⊖=−601.70\Delta_C H^{\ominus} = -601.70 kJ mol−1^{-1},…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.