The numerical value of Kc is 1.129 x10^4
Explanation
C3H6O +4O2→ 3 CO2 + 3H2O
KC is the ratio of concentration of the product over the reactant.
Each concentration of product and reactant are raised to the power of its coefficient.
Therefore the KC expression of equation above is
Kc=[ (Co2)^3 (H2O)^3] / [(C3H6O) (O2)^4)]
Kc =[(1.8^3) x (2.0^3)] / [(0.51) x (0.30^4)] =1.129 x10^4