NEET UG 2025 · Chemistry · Question 85
NEET 2025 Chemistry, question 85
Question 85 of the NEET 2025 paper (code 45) is a Chemistry question from Thermodynamics. Its idea, Hess's Law Application, was asked only this once in NEET 2017–2026. The NTA final answer key gives option 1.
Updated 2026-10-08
Q85 · Chemistry
The standard heat of formation, in kcal/mol of is :
[Given : standard heat of formation of ion (aq) = – 216 kcal/mol, standard heat of crystallisation of (s) = – 4.5 kcal/mol, standard heat of formation of (s) = – 349 kcal/mol]
- 1– 128.5Official answer
- 2– 133.0
- 3+ 133.0
- 4+ 220.5
Official answer: option 1 · NTA final answer key
Same idea
The only question on Hess's Law Application
No other NEET paper from 2017–2026 tested this exact idea.
Hess's Law Application: every question and how it was framed
The chapter
Thermodynamics in ten years of NEET
32 questions from 2017–2026, asked in 10 of 10 papers, about 3.1 a paper. Enthalpy and Hess's Law alone had 4.