SCS Yr 13 Kinetics VCOP

Analysing a small volume of reaction mixture – usually done by titration with standardised acids/bases.

• Quenching

• Sampling

• Titrating

• Precipitating

Stopping a reaction – often done by add a lot of water to dilute it. It may be possible to measure the concentration of a reactant/ product at that point.(e.g. by titration) and calculate the rate by dividing the change in concentration by the time.

• Quenching

• Sampling

• Titrating

• Precipitating

How fast a reaction is. It cannot be measured directly. It is a measure of the change in concentration per unit time.

Units = mol dm-3 s-1

• Equilibria

• Temperature

• Concentration

• Rate

This can be calculated by drawing a TANGENT on the graph at the start and working out the GRADIENT.

Gradient = y axis / x axis

Units = mol dm-3 s-1

• Equilibria

• Initial Rate

• Concentration

• Rate

This is the power to which the concentration is raised in the rate equation (“m” or “n” for the equation above).

• Zero order

• First order

• Second order

• Order of reaction

If you double the concentration, it has no effect on the rate.

• Zero order

• First order

• Second order

• Order of reaction

If you triple the concentration, the rate triples etc.

• Zero order

• First order

• Second order

• Order of reaction

If you double the concentration, the rate quadruples = [2]2

• Zero order

• First order

• Second order

• Order of reaction

This is the sum of all these orders of

reactions, i.e. (“m” + “n” for the equation above).

• Zero order

• First order

• Second order

• Overall order

The slowest step in a reaction. The particles that are involved in the RDS, appear in the rate equation.

• Catalyst

• Intermediate

• Mechanism

• Rate determining step