Increasing the pressure of chlorine in the reaction between chlorine and iron to form iron(III) chloride would not have a direct effect on the rate of the reaction. The rate of a chemical reaction is primarily influenced by factors such as concentration, temperature, and the presence of catalysts.
In this particular case, the reaction rate would be more affected by the concentration of chlorine rather than its pressure. Increasing the pressure of a gas would not directly change its concentration unless the volume is altered. However, if the pressure of chlorine is increased while keeping the concentration constant (e.g., by compressing the gas into a smaller volume), the rate of the reaction would not change significantly.
To alter the rate of the reaction, one would typically focus on factors like the concentration of reactants, temperature, or the presence of a catalyst. Adjusting these factors can affect the collision frequency and energy of the reactant particles, thereby influencing the reaction rate.