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The sublimation energy of I(2) (solid) i...

The sublimation energy of `I_(2)` (solid) is 57.3 KJ/mole and enthalpy of fusion is 15.5 KJ/mole. The enthalpy of vapourisation of `I_(2)` is

A

`41.8 kJ//mol`

B

`-41.8 kJ//mol`

C

`72.8 kJ//mol`

D

`-72.8 kJ//mol`

Text Solution

Verified by Experts

The correct Answer is:
A
According to Hess’s law total heat changes during a chemical reaction are independent of path of reaction.
Given: `I_(2)(s) to I_(2)(g),DeltaH_(1) = 57.3 kJ//mol" "…..(1)`
`I_(2)(s) to I_(2) I_(2)(l),DeltaH_(2) = +15.5 kJ//mol" "…….(ii)`
Required equation `I_(2)(l) to I_(2)(g), DeltaH = ?` subtract Eq. (ii) from Eq. (i)
`:. I_(2)(l) to I_(2)(g), DeltaH = 57.3 + (-15.5) = +41.8 kJ//mol`.
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