Q.
Calculate the standard internal energy charge for the reaction; OF2(g)+H2O(g)→O2(g)+2HF(g)at 298 K. The standard enthalpies of formation of OF2(g), H2O(g),HF(g) are +20,+250 , and −270kJmol−1 respectivley?
see full answer
Start JEE / NEET / Foundation preparation at rupees 99/day !!
21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya
answer is 312.4775 KJ.
(Unlock A.I Detailed Solution for FREE)
Ready to Test Your Skills?
Check your Performance Today with our Free Mock Test used by Toppers!
Take Free Test
Detailed Solution
ΔHReaction ∘=∑HProducts ∘−∑HReactants ∘=2×HHF∘(g)+H∘O2(g)−H∘OF2(g)+HH2O∘(g)∴H∘ of free elements =0∴HO2∘=0∴ΔHf∘=H∘, i.e., standard heat of formation = standard heat enthalpy of a compoundAlso, ΔHf∘ for F2O is +ve;ΔHf∘ for H2O is -ve, because heat of combustions are exothermic.ΔHR∘=[2×(−270)]+0−[20+(−250)]=−310kJ Now ΔH∘=ΔU∘+ΔnRT∴ΔHR∘=−310×103J;Δn=3−2=1R=8.314J;T=298K∴ −310×103=ΔU∘+1×8.314×298∴ ΔU∘=−312477.5joule∴ ΔU∘=−312.4775kJ
Watch 3-min video & get full concept clarity