Goodmarks

Chemistry · JEE

Hess's law of constant heat summation Revision for JEE

6+ syllabus-aligned questions available

Quick answer

Revise Hess's law of constant heat summation by covering every subtopic once, drilling formulas, then solving 6+ timed MCQs with full solutions.

Use this Hess's law of constant heat summation revision checklist before mocks and the final exam. Reinforce concepts with 6+ syllabus-aligned MCQs on Goodmarks.

Revision checklist

  1. 1.Core idea: Hess's law of constant heat summation
  2. 2.Relates to other subtopics in Chemical Thermodynamics
  3. 3.First law, enthalpy, Hess's law
  4. 4.Entropy and Gibbs energy
  5. 5.Master Hess's law of constant heat summation definitions and standard results
  6. 6.Solve 20 timed MCQs for Hess's law of constant heat summation

Syllabus context

Part of Chemical Thermodynamics in JEE Main Chemistry.

Free sample questions

Attempt 6 free MCQs for Hess's law of constant heat summation. Unlock the full bank with Pro.

Unlock full bank
Q1ChemistryUnit 4: Chemical Thermodynamics
Heat of combustion of CH4,C2H6\boldsymbol{C H}_{4}, \boldsymbol{C}_{2} \boldsymbol{H}_{6} and C3H8C_{3} H_{8} are respectively -210,-368.4 and −526.8Kcal-526.8 \mathrm{Kcal} mol 1_{1} Hence, heat of combustion of C8H16C_{8} H_{16} is approximately:
Q2ChemistryUnit 4: Chemical Thermodynamics
The statement "The change of enthalpy of a chemical reaction is same whether the reaction takes place in one or several steps" is:
Q3ChemistryUnit 4: Chemical Thermodynamics
If the heats of formation of C2H2C_{2} H_{2} and C6H6C_{6} H_{6} are 230KJmol−1230 \mathrm{KJ} \mathrm{mol}^{-1} and 85KJmol−185 \mathrm{KJ} \mathrm{mol}^{-1} respectively, the ΔH\Delta \mathrm{H} value for the trimerisation of C2H2C_{2} \mathrm{H}_{2} is:
Q4ChemistryUnit 4: Chemical Thermodynamics
(i) CaO(s)+H2O(l)=Ca(OH)2(s)\boldsymbol{C a O}(\boldsymbol{s})+\boldsymbol{H}_{2} \boldsymbol{O}(l)=\boldsymbol{C a}(\boldsymbol{O H})_{2}(\boldsymbol{s}) ΔH180∘C=−15.26kcal\Delta H_{180^{\circ} C}=-15.26 k c a l (ii) H2O(l)=H2(g)+12O2(g)\boldsymbol{H}_{2} \boldsymbol{O}(\boldsymbol{l})=\boldsymbol{H}_{2}(\boldsymbol{g})+\frac{1}{2} \boldsymbol{O}_{2}(\boldsymbol{g}) ΔH180∘C=68.37kcal\boldsymbol{\Delta} \boldsymbol{H}_{180^{\circ} C}=\mathbf{6 8 . 3 7} \boldsymbol{k c a l} (iii) Ca(s)+12O2(g)=CaO(s)C a(s)+\frac{1}{2} O_{2}(g)=C a O(s) ΔH180∘C=−151.80kcal\boldsymbol{\Delta} \boldsymbol{H}_{180^{\circ} C}=-151.80 k c a l From the following data, the heat of formation of Ca(OH)2(s)\boldsymbol{C a}(\boldsymbol{O H})_{2}(\boldsymbol{s}) at 18∘C\mathbf{1 8}^{\circ} \boldsymbol{C} is:
Q5ChemistryUnit 4: Chemical Thermodynamics
Given the following: C(s)+O2(g)→CO2(g);ΔH=\boldsymbol{C}(s)+\boldsymbol{O}_{2}(\boldsymbol{g}) \rightarrow \boldsymbol{C} \boldsymbol{O}_{2}(\boldsymbol{g}) ; \boldsymbol{\Delta} \boldsymbol{H}= −394kJ/mol-394 k J / m o l 2H2(g)+O2(g)→2H2O(l);ΔH=2 H_{2}(g)+O_{2}(g) \rightarrow 2 H_{2} O(l) ; \Delta H= −568kJ/mol⁡C2H5OH(l)+-\mathbf{5 6 8} k J / \operatorname{mol} C_{2} H_{5} O H(l)+ 3O2(g)→2CO2(g)+\mathbf{3} O_{2}(\boldsymbol{g}) \rightarrow \mathbf{2} \boldsymbol{C} \boldsymbol{O}_{2}(\boldsymbol{g})+ 3H2O(l);ΔH=−1058kJ/mol\mathbf{3} \boldsymbol{H}_{2} \boldsymbol{O}(\boldsymbol{l}) ; \boldsymbol{\Delta} \boldsymbol{H}=-\mathbf{1 0 5 8} \boldsymbol{k} \boldsymbol{J} / \boldsymbol{m o l} Using the given data, the heat of formation of ethanol is:
Q6ChemistryUnit 4: Chemical Thermodynamics
S+32O2→SO3+2x\boldsymbol{S}+\frac{\mathbf{3}}{\mathbf{2}} \boldsymbol{O}_{2} \rightarrow \boldsymbol{S} \boldsymbol{O}_{3}+\mathbf{2} \boldsymbol{x} kcal SO2+12O2→SO3+y\boldsymbol{S O}_{2}+\frac{1}{2} \boldsymbol{O}_{2} \rightarrow \boldsymbol{S} \boldsymbol{O}_{3}+\boldsymbol{y} kcal The heat of formation of SO2S O_{2} is:

Want unlimited Hess's law of constant heat summation practice?

Pro unlocks the full question bank, topic filters, and attempt history.

Get started freeView Pro plans

Frequently asked questions

How should I revise Hess's law of constant heat summation before JEE?

Follow the checklist on this page, revise formulas daily, and attempt mixed MCQs every 2–3 days.

Related topics