The factors that affect reaction rates are: surface area of a solid reactant. concentration or pressure of a reactant. temperature. nature of the reactants. presence/absence of a catalyst. Click to see full answer. Beside this, what are the 4 factors that affect the rate of reaction?Reactant concentration, the physical state of the reactants, and surface area, temperature, and the presence of a catalyst are the four main factors that affect reaction rate. how does surface area affect reaction rate? Effect of increasing surface area on the rate of a reaction. Increasing the surface area of a solid reactant exposes more of its particles to attack. This results in an increased chance of collisions between reactant particles, so there are more collisions in any given time and the rate of reaction increases. Considering this, what are the 5 factors that affect the rate of reaction? We can identify five factors that affect the rates of chemical reactions: the chemical nature of the reacting substances, the state of subdivision (one large lump versus many small particles) of the reactants, the temperature of the reactants, the concentration of the reactants, and the presence of a catalyst.How does pressure affect the rate of reaction?When you increase the pressure, the molecules have less space in which they can move. That greater density of molecules increases the number of collisions. When you decrease the pressure, molecules don’t hit each other as often and the rate of reaction decreases. Pressure is also related to concentration and volume.