Rate of reactants

Changes in surface area experiment

• React hydrochloric acid with calcium carbonate.

• Add large marble chips to the solution and time how it takes for it dissolve.

• Measure the volume of carbon dioxide produce over time.

• Repeat the experiment with smaller chips and powder

The smaller pieces would react quicker because they have a larger surface area

Concentration in a solution experiment

• React zinc with hydrochloric acid of different concentrations using a conical flask

• Measure the time taken for hydrogen gas to be produced using stopwatch and gas syringe

Higher concentrations will react faster

Temperature experiment

• React sodium thiosulfate and hydrochloric acid in a conical flask

• Place the flask over a paper cross and increase the temperature; timing how long it would take for the cross to disappear

High temperature increases the rate of reaction

Use of a catalyst reaction

• Decompose hydrogen peroxide with water and oxygen with magnesium oxide as a catalyst

• Repeat the experiment without using the catalyst

• Compare the rates of oxygen produced from both experiments

Effects of Surface area

The smaller pieces of a solid, the greater the surface area- which means more particles in the solid exposed to collision with other particles. The collision frequency will increase , leading to more successful collisions and the rate of reaction increases

Effects of temperature

Reactants at a higher temperature have more energy so the particles move faster lead to particles colliding more often and more particles with enough energy to react with. The collision frequency increase and there will be more successful collisions

Effects of concentration

The higher the concentration the solution, the more reactant particles in the same volume - making collisions more likely so the rate of reactions increases

Effects of pressure

Higher the pressure of gas means that the particles are more crowded- collision frequency will increase and so does the rate of reaction

Effects of a catalyst

When a catalyst is added to reaction, it speeds up an reaction without being used because it provides an alternative pathway with less activation energy so more particles would have the minimum amount of energy needed for a reaction to occur when they collide

Collision theory

For a reaction to occur , the reactants the must collie with enough energy- activation energy. The more collisions there are the faster the reaction and the lower the activation energy the greater chance of a successful collision.