JEE · NEET Previous Year Question
Given below are two statementsAssertion (A): The enthalpy of formation of graphite is taken as zero.Reason (R): Graphite is thermodynamically most stable allotrope of carbonThe correct answer is
Topic: JEE PYQ
Answer: A. Full step-by-step solution below.
- ABoth (A) and (R) are correct and (R) is the correct explanation of
- BBoth and are correct but is not the correct explanation of
- C
- D
Correct answer: A
Solution
(a) The enthalpy of formation of a substance is the amount of energy required to prepare it from its constituents in their most stable states.Since graphite is the most stable allotrope of carbon, its enthalpy of formation is zero.
Thus, both Assertion (A) and Reason (R) are correct statements and Reason (R) explains Assertion (A).
More s-Block Elements PYQs
- Which of the following metals exist in liquid state during summer season?
- The element playing significant role in neuromuscular function and interneuronal transmission is :
- The hybridisations of -orbitals in and respectively ar…
- The chemical nature of hydrogen peroxide is :
- Assertion : Alkali metals and their salts impart characteristic flame colours. Reason (R): Alkali metals have…