Since the expression for the reaction quotient depends on the reaction equation the magnitude of K also depends on how the reaction equation is written.
(1) CaCO3(s) 
CaO(s) + CO2(g)
K1 = [CO2]
(2) CaCO3(s) CaO(s) + CO2(g)
If the coefficients are all multiplied by n,
the reaction quotient expression is raised to the n power and the new K = (K1)n.
n = 2 in the example below.
2CaCO3(s) 2CaO(s) + 2CO2(g)
K3 = [CO2 ]2
CaO(s) + CO2(g)K1 = [CO2]
If the equation is reversed,
the reaction quotient expression is inverted, and the new K = 1/K1 = (K)–1
(2) CaCO3(s)
CaO(s) + CO2(g)| K2 | = | 1 | = [CO2]–1 |
| [CO2] |
If the coefficients are all multiplied by n,
the reaction quotient expression is raised to the n power and the new K = (K1)n.
n = 2 in the example below.
2CaCO3(s)
2CaO(s) + 2CO2(g)K3 = [CO2 ]2