Chapter 18- Speed of Reaction

Enzymes

Biological catalysts which are sensitive to pH and temperature.

Fermentation

________ is very slow while precipitation reactions are very fast.

Catalysts

A substance that increases the speed of the reaction while remaining chemically unchanged itself.

Temperature

________ of the reaction (directly proportional to the speed of reaction): When the ________ of the reactants is more, the particles gain kinetic energy and collide more frequently.

The speed of reactions can be measured by measuring any of the following per unit time

amount of reactant used up, amount of product obtained, volume of gas produced

Concentration of the reactants (directly proportional to the speed of reaction)

When the concentration of the reactants is more, there are more particles per unit volume which increases the frequency of collisions

Pressure of gaseous reactants (directly proportional to the speed of reaction)

When the pressure of the reactants is more, there are more particles per unit volume which increases the frequency of collisions

Particle size (directly proportional to the speed of reaction)

When the particle size is smaller, more surfaces are exposed, increasing the surface area to volume ratio which in turn increases the frequency of collisions

Temperature of the reaction (directly proportional to the speed of reaction)

When the temperature of the reactants is more, the particles gain kinetic energy and collide more frequently

Rate of reaction

The amount of product formed per unit time in a chemical reaction.

Fermentation

The chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat.

Activation Energy

the energy that an atomic system must acquire before a process can occur.

Successful collisions

The collision when two reactants successfully collide with enough energy and the right orientation to make a product.