2.8a: recall the factors that influence the rate of chemical reaction, including concentration, temperature, pressure, surface area and catalysts

CONCENTRATION

Increasing concentration increases the rate of reaction

The percentage of successful collisions remains the same, but the frequency of collisions increases

TEMPERATURE

Increasing temperature increases the rate of reaction

• average kinetic energy of the particles increases, so they collide more frequently with more energy, so more particles reach the activation energy

PRESSURE

Increasing pressure compresses gas particles, which increases the concentration of the gas particles

• increases the frequency of collisions, so the rate of reaction increases

SURFACE AREA

As surface area increases, the frequency of collisions increases

• rate of reaction increases

CATALYSTS

Catalysts work by providing an alternative route for the reaction with a low activation energy, without being used up

• a substance that increases the rate of a chemical reaction by providing an alternative pathway with a lower activation energy, without undergoing chemical change

Why are catalysts so important in industry?:

• increases the rate of chemical reactions
• allows reactions to be performed at lower temperatures
• only a small amount of catalyst is needed

What are some disadvantages of using catalysts?:

• can be expensive or toxic
• it takes time to find the best catalyst

What effect does a catalyst have on reversible reactions?:

• speeds up the rate of the forward and backwards reactions equally, so equilibrium is reached faster, but has no effect on the actual position of equilibrium