In conversion of limestone to lime , `CaCO_3(s) rarrCaO(s)+CO_2(g)` the values of `DeltaH^@ and DeltaS^@` are +179.1 KJ/mol , 160.2J/K respectively at 298 K and 1 bar. Assuming that `DeltaH^@ and DeltaS^@` do not change with temperature , temperature above which conversion of limestone to lime will be spontaneous is

Options

A. 847 K
B. 1118 K
C. 1008
D. 1200 K

Answer

B

Explanation

`DeltaG^(@) = DeltaH^(@) -TDeltaS^(@)`
for a spontaneous process `DeltaG^(@) lt 0`
`implies DeltaH^(@)-TDeltaS^(@) lt 0 implies TDeltaS^(@) gt DeltaH^(@) implies T gt (DeltaH^(@))/(DeltaS^(@)) implies T gt (179.1 xx 1000)/(160.2) implies T gt 1117.9 K = 1118 K`.