Where does the equilibrium shift if there is a decrease in reactants?

When there is a decrease in the concentration of reactants in a chemical equilibrium, the system will respond according to Le Chatelier's Principle. This principle states that if a dynamic equilibrium is disturbed by changing the conditions, the system shifts in a direction that counteracts the change.

In this case, with fewer reactants available, the equilibrium will shift to the left in order to produce more reactants from the products. This means that the system will favor the reverse reaction, leading to an increase in the concentration of the reactants while decreasing the concentration of the products. This shift helps to restore the balance of the equilibrium as much as possible under the new conditions. Therefore, the correct choice indicates that the equilibrium shifts to the left, thereby increasing reactants.