Rate of Reaction

Activity 7.3:Solving numerical problems related to rate of reactionsIn the presence of manganese(IV) oxide, MnO2, hydrogen peroxide, H2O2 decomposes to water and oxygen. The oxygen gas released is collected in a gas syringe and the volume recorded at intervals of 0.5 minute. The data collected is shown in Table 7.3.1. Based on Table 7.3, plot … Read more

Activity 7.1:Aim: Determining the time for reaction with reference to some observable and measurable changes.Materials: Zinc powder, Zn, 0.1 mol dm–3 sulphuric acid, H2SO4, marble chips, CaCO3, 2.0 mol dm–3 nitric acid, HNO3, potassium iodide powder, KI, lead(II) nitrate powder, Pb(NO3)2 and distilled waterApparatus: Retort stand with clamp, burette, basin, 250 cm3 conical flask, 10 … Read more

Keeping food in a refrigerator If food is kept in the fridge, the food will keep longer because the low temperature will slow down the rate of the chemical reaction which destroys food. Cooking food in a pressure cooker In a pressure cooker, the high pressure causes the water in the cooker to boil at … Read more

The collision theory states that: The particles of the reacting need to touch to enable the formation or breaking of the bonds for a reaction to happen. Collisions of particles of a reacting substance need to achieve certain minimum energy (Activation Energy) in order to produce a reaction. Particles that collide also need to have … Read more

Pressure of Gas For reactions involve gas, the rate of reaction is affected by the pressure of the gas. Pressure DOES NOT affect the rate of reaction where the reactants are in the form of solids or liquids. The higher the pressure of the gas, the higher the rate of reaction

Presence of Catalyst A catalyst is a substance which can change the rate of reaction. There are 2 types of catalyst: Positive catalyst – Increase the rate of reaction. Negative catalyst – Reduce the rate of reaction. Experiment 1 Set 1: Zinc + Hydrochloric AcidSet 2: Zinc + Hydrochloric Acid + Copper Sulphate (Catalyst) Chemical … Read more

Temperature of the Reactant The higher the temperature of the solution, the higher the rate of reaction. Experiment By measuring the time taken for the formation of sulphur precipitate (yellow solid) when sulphuric acid, H2SO4 reacts with sodium thiosulphate(VI), Na2S2O3 of different temperature, we can investigate the effect of temperature of the reactant on the … Read more

Concentration of Reactants The higher the concentration of the solution, the higher the rate of reaction. Experiment By measuring the time taken for the formation of sulphur precipitate (yellow solid) when sulphuric acid, H2SO4 reacts with sodium thiosulphate(VI), Na2S2O3 of different concentration , we can investigate the effect of concentration of the reactant on the … Read more

Total Surface Area For reaction involves solid reactant, when the solid reactants is broken up into smaller pieces, the total surface area of the reactant becomes bigger. The bigger the total surface area of the reactant, the higher the rate of reaction. The smaller the size of the particle, the bigger the total surface area. … Read more

There are 4 factors that can affect the rate of a reaction, namely the total surface area of the reactant (solid only) the concentration of the reactant (solution only) the temperature of the reactant presense of catalyst in the reactant the pressure of the reactant (gas only) Total Surface Area For same amount of reactant, particles … Read more