Question

True/False? outline work please

The gibbs-Helmholtz equation predicts that the equilibrium constant for calcium carbonate decomposition does not exceed 1.0 at 1000 K.

Answer 1

Answer: True

because, the decomposition of CaCO3 is by the following reaction;

CaCO3 → CaO + CO2(g)

and the standard Gibbs free energy of the reaction is approximated as :

ΔG°r = 177,100 − 158 T (J/mol)......(1)

also ΔG°r = -RT lnK ......(2) where R = 8.314 (J/mol.K)

K = equilibrium constant.

So, for T= 1000 K

using equation (1),

ΔG°r = 177100 - 158 * 1000

= 19100 (J/mol)

equating this value to equation (2),

19100 = - 8.314 * 1000 lnK

we get, K = 0.1 which is less than 1.

So the given statement is TRUE