ΔHcrys(BaSO4)=ΔHf(BaSO4)−[ΔHf(Ba+2)+ΔHf(SO4−2)]−4.5=[−349]−[ΔHf(Ba+2)+(−216)]ΔHf(Ba+2)=−128.5kCal mol−1
NEET UG 2025 — Chemistry Physical Chemistry
The standard heat of formation, in kcal/molof Ba2+ is : [Given : standard heat of formation of SO42− ion (aq) =−216kcal/mol, Standard heat of crystallisation of BaSO4( s)=−4.5kcal/mol, standard heat of formation of BaSO4( s)=−349kcal/mol]
Held on 30 Apr 2025 · Verified 9 Jul 2026.
-128.5
-133.0
+133.0
+220.5
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