National 5; Rates of reaction Factors affecting reaction rate. The speed of a chemical reaction is affected by temperature, concentration, particle size and the presence of a catalyst.

Discusses the factors influencing chemical reaction rates and equilibrium. It explains how different reactions occur at varying rates due to factors such as the nature of reactants, surface area ...

Factors affecting the rate of photosynthesis. Water. You won't often see graphs for its effects, ... Most important is its role as a solvent for all the chemical reactions in cells.