In conversion of lime-stone to lime,
`CaCO_(3(s)) to CaO_((s)) + CO_(2(g))` the values of `DeltaH^@` and `DeltaS^@` are `+179.1 kJmol^(-1)` and `160.2 J//K` respectively at `298K` and 1 bar. Assuming that `DeltaH^@` and `DeltaS^@` do not change with temperature, temperature above which conversion of lime-stone to lime will be spontaneous is :

Options

A. 845 K
B. 1118 K
C. 1008 K
D. 1200 K

Answer

B

Explanation

`Delta G^(@) = Delta H^(@) - T Delta S^(@)`
For a spontaneous process `Delta G^(@) lt 0`
`Delta H^(@) - T Delta S^(@) lt 0" "therefore T Delta S gt Delta H^(@)`
`therefore T gt (Delta H^(@))/(Delta S^(@))" "therefore T gt (179.1 xx1000)/(160.2)`
`therefore T gt 1117.9 K ~~ 1118 K`