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consider the chemical reaction OF2+H20¶O2+2HF ∆H°=-323 KJ what is the heat of reaction if equation is multiplied by 3 |
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Answer» Answer:Answer Correct option is D -79 kcal From Hess' Law, ΔH=∑B.E. R −∑B.E. P
= (2 X 44 + 2 X 111) - (119 + 2 X 135) = -79 kcal Explanation:Answer Solution:- OF 2
(G) +H 2 O (g) ⟶O 2
(g) +2HF (g)
ΔH R =∑ΔH f
(product) −∑ΔH f
(reactant)
∴ΔH R =(2×(−268.6))−(23+(−241.8)) ⇒ΔH R =−756kJ/mol Hence the standard enthalpy CHANGE will be −756kJ/mol Now, as we know that, ΔH=ΔU+Δn g RT ⇒ΔU=ΔH−Δn g RT Now from the given reaction, Δn g =n P −n R =(2+1)−(1+1)=1 T=300K(Given) R=8.314×10 −3 J/mol−K ∴ΔU=(−756)−(1×8.314×10 −3 ×300) ⇒ΔU=−756−2.494=−753.506kJ/mol Hence the standard internal ENERGY change will be −753.506kJ/mol. |
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