Final answer:
To determine K for a reaction that is the sum of two or more reactions, multiply the equilibrium constants (K values) of the individual reactions. For an equation with changed coefficients, the new K is the original K raised to the power of the coefficient.
Step-by-step explanation:
To find the equilibrium constant (K) for a reaction that is the sum of two or more reactions, you should multiply the equilibrium constants (K values) of the individual reactions. This method is based on the principle that the overall reaction's K is the product of the K values from the contributing reactions. For example, if you have two reactions with equilibrium constants K1 and K2, and their sum represents a new overall reaction, then the equilibrium constant for the overall reaction, K3, would be calculated as K3 = K1 * K2.
Let's look at an example where K1 = (2.0 × 10-25) and K2 = (6.4 × 100). The overall K3 would be K3 = K1 * K2 = (2.0 × 10-25) * (6.4 × 100) = 1.3 × 10-15.
Remember, if you are dealing with changes in the coefficients of a balanced chemical equation, the new equilibrium constant K" is the original equilibrium constant K raised to the power of the coefficient, n. For example, K" = (K')