Project ForgeDetermine the correctness or otherwise of the following Assertion [a] and Reason [r]. Assertion: Significant combustion of coke takes place only if it is heated at higher temperature in presence of air. Reason: C+O2→CO2 is an exothermic reaction.
- ABoth [a] and [r] are true and [r] is the correct reason for [a]
- Both [a] and [r] are true but [r] is not the correct reason for [a]
- C[a] is correct but [r] is false
- DBoth [a] and [r] are false
Explanation
Both statements are factually true: coke does need a higher temperature to sustain significant combustion (a kinetic/activation-energy requirement), and C+O2→CO2 is indeed exothermic (a thermodynamic fact). But exothermicity is not WHY high temperature is needed to initiate significant combustion — that requirement comes from the reaction's activation energy/kinetics, not from the sign of ΔH. So [r] is true but is not the correct reason for [a].
Source: GATE CH 2014 (2014)
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