Final answer:
The equilibrium in a chemical reaction shifts in the direction that minimizes stress according to Le Chatelier's principle. If the equilibrium constant K is less than 10^-3, the reaction favors the reactants and the equilibrium shifts to the left.
Step-by-step explanation:
In the context of chemical reactions and equilibrium, the equilibrium constant, known as K, is crucial in determining the direction in which the reaction naturally tends. If the value of K is less than 10-3, it indicates a shift toward reactants, meaning that the reverse reaction is favored and the equilibrium position lies to the left.
Using Le Chatelier's principle, we know that when an equilibrium is stressed by changing conditions, such as pressure, temperature, or concentration of reactants/products, it will shift to minimize that stress. For example, in the reaction N2 + 3H2 → 2NH3, increasing the pressure would cause the equilibrium to shift to the left (toward reactants) because there are fewer moles of gas on the reactant side (1 mole of N2 + 3 moles of H2) than the product side (2 moles of NH3).