Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
The heats of combustion of carbon and carbon monoxide are -393.5 and-283.5 kJ mol-1, respectively. The heat of formation in kJ of carbon monoxide per mole is:
ChemistryThermodynamics (C)JEE MainJEE Main 2016 (03 Apr)
Options:
  • A - 676.5
  • B -110
  • C 110.5
  • D 676.5
Solution:
2856 Upvotes Verified Answer
The correct answer is: -110
Given: Heat of combustion of carbon and carbon monoxide are -393.5 and-283.5 kJ mol-1, respectively.

(i) C+O2CO2;     H1=-393.5 kJ mol-1

(ii) CO+12O2  CO2;     H2=-283.5 kJ mol-1

To find the heat of formation of CO per mole.
C+12O2CO
Δ H f of CO

From equations (i) and (ii),
=-393.5--283.5
= - 1 1 0  kJ mol-1

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.