Q35.At 25 °C and 1 atm pressure, the enthalpies of combustion are as given below: Substance H2 C (graphite) C2H6(g) ΔcHΘ −286. 0 −394. 0 −1560. 0 kJmol−1 The enthalpy of formation of ethane is JEE Main 2022 (24 Jun Shift 2) JEE Main Previous Year Paper (1) +54. 0 kJ mol−1 (2) −68. 0 kJ mol−1 (3) −86. 0 kJ mol−1 (4) +97. 0 kJ mol−1
What This Question Tests
This question applies Hess's Law to calculate the enthalpy of formation of ethane using the given standard enthalpies of combustion for H2, C (graphite), and C2H6.
Concepts Tested
Formulas Used
ΔfH° (reaction) = Σ ΔfH° (products) - Σ ΔfH° (reactants)
📚 NCERT Sections This Tests
1.35 — Henry’S Law Constant For The Molality Of Methane In Benzene At 298 K Is
Chemistry Class 11 · Chapter 1
1.35 Henry’s law constant for the molality of methane in benzene at 298 K is 4.27 × 105 mm Hg. Calculate the solubility of methane in benzene at 298 K under 760 mm Hg.
3.23 — The Rate Constant For The Decomposition Of Hydrocarbons Is 2.418 × 10–5S–1
Chemistry Class 11 · Chapter 3
3.23 The rate constant for the decomposition of hydrocarbons is 2.418 × 10–5s–1 at 546 K. If the energy of activation is 179.9 kJ/mol, what will be the value of pre-exponential factor.
3.20 — For The Decomposition Of Azoisopropane To Hexane And Nitrogen At 543
Chemistry Class 11 · Chapter 3
3.20 For the decomposition of azoisopropane to hexane and nitrogen at 543 K, the following data are obtained. t (sec) P(mm of Hg) 0 35.0 360 54.0 720 63.0 Calculate the rate constant.
📋 Question Details
- Chapter
- Thermodynamics & Thermochemistry
- Topic
- Hess's Law
- Year
- 2022
- Shift
- 24 Jun Shift 2
- Q Number
- Q35
- Type
- MCQ
- NCERT Ref
- Class 11 Chemistry Ch 6: Thermodynamics
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