A few factors influence the rate of reaction, including
:
<em>Temperature.</em> Most reactions increase in rate as
temperature increases; most reactions slow down as
temperature decreases.
<em>Concentrations of the reactant.</em> Raising the concentration of a
substance will increase the speed of the reaction; lowering the
concentration of a substance will decrease the speed of the
reaction. The limiting reactant is the reactant that is completely used
up in a reaction. When this is completely used up, the reaction will
stop.
<em>Catalysts</em>. These are substances that speed up the rate of the
reaction by lowering the activation energy. If a catalyst is added, the
rate of reactions will increase. If a catalyst is removed, the rate of
reactions will decrease. Enzymes are biological catalysts used in
living things to speed up internal reactions.
<em>Inhibitors</em>. These are substances that slow down the rate of a
reaction. If an inhibitor is added to a reaction, its rate will decrease.
If an inhibitor is removed from a reaction, its rate will increase.
Thus, the right answer is B. Lowering the concentration of the reactants