Rate of Reaction

Rate of ReactionThe rate of a chemical reaction measures: how fast reactants are being used up how fast products are being made Rate of reaction is usually measured as the change in concentration of a reactant or product with time.Rate = change in concentration of reactant or product                       time for the change to take placeSometimes it is more convenient to use a different physical quantity that is proportional to concentration, or a different time measurement.Square brackets are used to represent concentration.As a reaction proceeds, the concentrations of the reactants decrease: fewer collisions take place per second between reaction particles the rate slows down The rate of a reaction can be determined by measuring the concentration of a reactant, or product, at time intervals during the course of a reaction. The experimental results are processed and a graph is plotted of concentration against time. At any instant of time, the rate is equal to the slope of the curve The slope is measured by drawing a tangent to the curve at this time The gradient, or slope, of a tangent is then calculated.

New Page