Q53.Combustion of 1 mole of benzene is expressed at C6H6(l) + 152 O2( g) →6CO2( g) + 3H2O(l). The standard enthalpy of combustion of 2 mol of benzene is −′x′kJ. x = ______ Given: 1. standard Enthalpy of formation of 1 mol of C6H6(l), for the reaction 6C (graphite) +3H2( g) →C6H6(l) is 48.5 kJ mol−1 . 2. Standard Enthalpy of formation of 1 mol of CO2( g), for the reaction C (graphite) +O2( g) →CO2( g) is −393.5 kJ mol−1 . 3. Standard and Enthalpy of formation of 1 mol of H2O(l), for the reaction H2( g) + 12 O2( g) →H2O(l) is −286 kJ mol−1 .
What This Question Tests
This question requires calculating the standard enthalpy of combustion for benzene using given standard enthalpies of formation for reactants and products and then scaling for 2 moles.
Concepts Tested
Formulas Used
ΔH°_reaction = ΣΔH°_f(products) - ΣΔH°_f(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.
1.30 — Calculate The Amount Of Benzoic Acid (C6H5Cooh) Required For Preparing 250
Chemistry Class 11 · Chapter 1
1.30 Calculate the amount of benzoic acid (C6H5COOH) required for preparing 250 mL of 0.15 M solution in methanol.
📋 Question Details
- Chapter
- Thermodynamics & Thermochemistry
- Topic
- Enthalpy of Combustion
- Year
- 2024
- Shift
- 05 Apr Shift 2
- Q Number
- Q53
- Type
- Numerical
- NCERT Ref
- Class 11 Chemistry Ch 6: Thermodynamics
More from this Chapter
Q89.A heat engine absorbs heat Q1 at temperature T1 and heat Q2 at temperature T2 . Work done by the engine is J (Q1 + Q2). This data (1) violates 1st law of thermodynamics (2) violates 1st law of thermodynamics if Q1 is −ve (3) violates 1st law of thermodynamics if Q2 is − ve(4) does not violate 1st law of thermodynamics
Q93.If at 298 K the bond energies of C −H, C −C, C = C and H −H bonds are respectively 414, 347, 615 and 435 kJ mol−1 , the value of enthalpy change for the reaction H2C = CH2( g) + H2( g) →H3C −CH3( g) at 298 K will be (1) −250 kJ (2) +125 kJ (3) −125 kJ (4) +250 kJ
Q94.In an irreversible process taking place at constant T and P and in which only pressure-volume work is being done, the change in Gibbs free energy (dG) and change in entropy (dS), satisfy the criteria (1) (dS)V,E > 0, (dG)T,P < 0 (2) (dS)V:E = 0, (dG)TPP = 0 (3) (dS)V,E = 0, (dG)T,P > 0 (4) (dS)V,E < 0, (dG)T,P < 0
Q96.The enthalpy change for a reaction does not depend upon (1) use of different reactants for the same product (2) the nature of intermediate reaction steps (3) the differences in initial or final temperatures of (4) the physical states of reactants and products involved substances