The molar heat capacities of Iodine vapour and solid are 7.8 and 14 cal/mol respectivelyifenthalpy of sublimation of iodine is 6096 cal/mole at `200^(@)C,` then what is `Delta U` (internal energy change) at` 250^(@)C` in cal/mol

Options

A. `5360`
B. `4740`
C. `6406`
D. `5880`

Answer

B

Explanation

`I _(2 (s)) to I _(2 (g)) , Delta H _(2) = Delta H _(1) + Delta C _(p) (T _(2) - T _(1))`
`Delta C _(P) (I _(2 .g)) - C _(P) (I _(2, 6)) =- 6.2 cal//"mole", Delta H _(2) = 6096 -6.2 (50) = 5786` cal/mole
`Delta H = Delta U + 1 xx 2 xx 523 , 5786 = Delta U + 1 xx 2 xx 523 , Delta U = 5786 - 1046 = 4740 cal`