Source: https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-7-rate-of-reaction-2 [Revision notes](https://senecalearning.com/en-gb/revision-notes.md) › [GCSE](https://senecalearning.com/en-gb/revision-notes/gcse.md) › [Science Practicals](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals.md) › [National Curriculum](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum.md) › Rate of Reaction 2 # Rate of Reaction 2 Science Practicals: GCSE, topic 2.1.7 ## Rate of Reaction - Key Factors The main factors that affect the rate of chemical reactions are: ### Concentration of dissolved reactants ![Concentration of dissolved reactants](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/6.1.1%20Calculating%20rates%20of%20reactions/vitamin-b-871135_640-min.jpg) - Increasing the concentration increases the frequency (number) of collisions. This increases the rate of reaction. ### Pressure of gas reactants ![Pressure of gas reactants](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/6.1.1%20Calculating%20rates%20of%20reactions/blood-pressure-1006791_640-min.jpg) - Increasing pressure is like increasing the concentration. - It increases the frequency (number) of collisions. This increases the rate of reaction (makes the reaction faster). ### Temperature ![Temperature](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/6.1.1%20Calculating%20rates%20of%20reactions/thermometer-1614708_640-min.jpg) - Increasing the temperature increases the frequency (number) of collisions. - Increasing the temperature increases the energy of reactant particles. This means that a greater proportion (more) of the particles will have more energy than the activation energy that is needed. - Together, these lead to more successful collisions. This increases the rate of reaction. ### Surface area of solid reactants ![Surface area of solid reactants](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/6.1.1%20Calculating%20rates%20of%20reactions/cube-surface-2886285_640-min.jpg) - Increasing the surface area increases the frequency (number) of collisions. This increases the rate of reaction. - This is often done by breaking up solids into smaller lumps (e.g. powders). - This increase in surface area to volume ratio makes sure that more particles are exposed to attack. ### Catalysts ![Catalysts](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/6.1.1%20Calculating%20rates%20of%20reactions/beakers-309864_640-min.jpg) - Catalysts are substances that increase the rate of a chemical reaction without being used up in the process. ## Catalysts Catalysts increase the rate of chemical reactions by lowering the activation energy. They do this by providing a different reaction pathway. ### Not used up ![Not used up](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/6.1.1%20Calculating%20rates%20of%20reactions/cleanliness-2799459_640-min.jpg) - Catalysts are not used up during chemical reactions. This means that: - They can be reused indefinitely. - They are not found in chemical equations. - However, catalysts will often need cleaning or regenerating, which has knock-on effects for energy expenditure and environmental impact. ### Different catalysts ![Different catalysts](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/6.1.1%20Calculating%20rates%20of%20reactions/christian-stahl-313383-min.jpg) - Different reactions need different catalysts: - Iron is used in the process that makes ammonia. - Platinum and palladium are used in catalytic converters in cars. - Enzymes catalyse reactions in biological systems. ### Powders ![Powders](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/6.1.1%20Calculating%20rates%20of%20reactions/rangoli-593790_640-min.jpg) - Catalysts often come as powders, pellets or fine gauzes because these types of substance have particularly high surface areas. ## Test yourself on Rate of Reaction 2 - Limestone and marble structures crumble when reacted with acid. How will the recent increase in concentration of acid in rainwater affect the rate at which limestone and marble are being worn away? - Select the correct statement for each pair about catalysts. - Why do catalysts often come in the form of powders, pellets and fine gauzes? - What are the knock-on effects of catalysts needing regular cleaning or regenerating? - How do catalysts lower the activation energy needed for a chemical reaction? [Practise this topic for free](https://app.senecalearning.com/classroom/course/35d9e7b0-1dfb-11e8-b5b7-7546c70e1a36/section/217e39d5-8a8a-4316-b958-94b0ffb43bdd/session) - Previous topic: [2.1.6 Rate of Reaction](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-6-rate-of-reaction.md) - Next topic: [2.1.8 Chromatography](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-8-chromatography.md) ## Science Practicals: GCSE contents ### 1 Biology - 1.1 Practicals - [1.1.1 Microscope & Bacteria](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-1-microscope-and-bacteria.md) - [1.1.2 Bacteria](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-2-bacteria.md) - [1.1.3 Osmosis Tests](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-3-osmosis-tests.md) - [1.1.4 Osmosis & Food Tests](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-4-osmosis-and-food-tests.md) - [1.1.5 Enzymes](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-5-enzymes.md) - [1.1.6 Enzymes 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-6-enzymes-2.md) - [1.1.7 Photosynthesis & Plant Responses](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-7-photosynthesis-and-plant-responses.md) - [1.1.8 Photosynthesis Experiments](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-8-photosynthesis-experiments.md) - [1.1.9 Reaction Time](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-9-reaction-time.md) - [1.1.10 Quadrats](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-10-quadrats.md) - [1.1.11 Decay](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/1-1-11-decay.md) ### 2 Chemistry - 2.1 Practicals - [2.1.1 Salts](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-1-salts.md) - [2.1.2 Neutralisation](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-2-neutralisation.md) - [2.1.3 Titration](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-3-titration.md) - [2.1.4 Electrolysis](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-4-electrolysis.md) - [2.1.5 Electrolysis 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-5-electrolysis-2.md) - [2.1.6 Rate of Reaction](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-6-rate-of-reaction.md) - [2.1.7 Rate of Reaction 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-7-rate-of-reaction-2.md) - [2.1.8 Chromatography](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-8-chromatography.md) - [2.1.9 Identifying Gases](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-9-identifying-gases.md) - [2.1.10 Identifying Gases 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-10-identifying-gases-2.md) - [2.1.11 Identifying Ions](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-11-identifying-ions.md) - [2.1.12 Carbonates, Halides & Sulfates](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-12-carbonates-halides-and-sulfates.md) - [2.1.13 Flame Emission Spectroscopy](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-13-flame-emission-spectroscopy.md) - [2.1.14 Water Purification](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-14-water-purification.md) - [2.1.15 Water Purification 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/2-1-15-water-purification-2.md) ### 3 Physics - 3.1 Practicals - [3.1.1 Specific Heat Capacity](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-1-specific-heat-capacity.md) - [3.1.2 Thermal Capacity & Insulation](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-2-thermal-capacity-and-insulation.md) - [3.1.3 Latent Heat](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-3-latent-heat.md) - [3.1.4 Resistance & Current](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-4-resistance-and-current.md) - [3.1.5 Resistance & Current 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-5-resistance-and-current-2.md) - [3.1.6 Density](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-6-density.md) - [3.1.7 Density 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-7-density-2.md) - [3.1.8 Force & Extension - Springs](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-8-force-and-extension-springs.md) - [3.1.9 Waves - Ripple Tank](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-9-waves-ripple-tank.md) - [3.1.10 Light](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-10-light.md) - [3.1.11 Light Reflection & Refraction](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-11-light-reflection-and-refraction.md) - [3.1.12 Radiation](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-12-radiation.md) - [3.1.13 Radiation 2](https://senecalearning.com/en-gb/revision-notes/gcse/science-practicals/national-curriculum/3-1-13-radiation-2.md)