Passage I
A reaction is at equilibrium when the rate of the forward reaction equals the rate of the reverse reaction. At equilibrium, the ratio of product concentration(s) to reactant concentration(s) is the equilibrium constant, K.
Consider the following reaction at equilibrium:
X + Y 
Z
For this reaction, K is given by:
The brackets ([ ]) around the symbol for a substance indicate the equilibrium concentration of the substance.
This reaction was studied in 10 trials. Trials 1-5 were conducted at the same temperature (see Table 1 ) , and Trials 6-10 were conducted at different temperatures (see Table 2).
2. Suppose that Trial 7 had been conducted at -5°C. Based on Table 2, K would most likely have been closest to which of the following?
Your Answer is
Correct Answer is H
Explanation
Observing table 2, it is found that as the temperature increases, the value of K decreases, so when the temperature of trail 7 becomes -5, K should be greater than 0.59, but should not exceed 10.5 in trail 6