C9 Rate of Reaction Lecture Notes

This set of vocabulary flashcards covers the fundamental concepts, measurement methods, formulas, and units involved in studying the rate of chemical reactions.

Rate of reaction

A measurement of how quickly the reactants in a chemical process turn into the products.

Mean rate of reaction (Reactant basis)

$$\text{mean rate of reaction} = \frac{\text{quantity of reactant used}}{\text{time taken}}$$

Mean rate of reaction (Product basis)

$$\text{mean rate of reaction} = \frac{\text{quantity of product formed}}{\text{time taken}}$$

Gas syringe

A piece of equipment connected to a reaction mixture via rubber tubing used to collect and measure the volume of gas produced.

$$cm^3/s$$

The unit for rate of reaction when the volume is measured in cubic centimeters and time is measured in seconds.

Precipitate

An insoluble solid produced during a reaction in solution that makes the mixture go cloudy.

Turbidity method

A way to measure reaction rate by timing how long it takes for a precipitate to form such that a solid black cross on white paper is no longer visible from above.

Mass balance

An instrument used to measure the change in mass of a reaction mixture as a gaseous product is given off.

$$g/s$$

The unit for rate of reaction when the change in mass is measured in grams and time is measured in seconds.

Steep gradient

A feature on a reaction graph representing a high rate of reaction where the process happens quickly.

Shallow gradient

A feature on a reaction graph representing a low rate of reaction where the process happens slowly.

Activation energy

The minimum amount of energy that colliding particles must have in order to react.

Catalyst

A substance that can be added to a reaction to increase its rate by providing an alternative pathway with lower activation energy; it is not used up in the process.