If there are more frequent collisions then the rate of reaction will increase. If the particles which collide have more energy, or if the activation energy is lowered, then there will be more successful collisions. Describe and explain A higher concentration of solution means the effect of changes that there will be more particles of solute in in concentration of the same volume. This will lead to more solutions on the rate of frequent collisions so the rate of reaction will reaction increase. Describe and explain A higher pressure means that there will be the effect of changes more particles of gas in the same volume. in pressure of reacting This will lead to more frequent collisions so gases on the rate of the rate of reaction will increase. reaction Describe and explain Smaller pieces of solid mean that the solid the effect of changes has a higher surface area. This means that in the size of pieces of more of the reactant particles are exposed a reacting solid on the so there are more frequent collisions. This rate of reaction increases the rate of reaction. Describe the A catalyst is a chemical which speeds up characteristics of the rate of a reaction without being used catalysts and their up or altered itself. effect on rates of Catalysts are specific to the reaction, so a reaction chemical that catalyses one reaction may not catalyse another reaction. Recall that enzymes Enzymes are biological catalysts that up act as catalysts in reactions in biological systems. biological systems Explain catalytic action A catalyst lowers the activation energy, in terms of activation which leads to more successful collisions. energy This increases the rate of reaction. Keywords: catalyse, catalyst, collide, directly proportional, enzyme, gas syringe, inversely proportional, pressure, rate of reaction, reaction time, successful collision, surface area
If there are more frequent collisions then the rate of reaction will increase. If the particles which collide have more energy, or if the activation energy is lowered, then there will be more successful collisions. Describe and explain the effect of changes in concentration of solutions on the rate of reaction A higher concentration of solution means that there will be more particles of solute in the same volume. This will lead to more frequent collisions so the rate of reaction will increase. Describe and explain the effect of changes in pressure of reacting gases on the rate of reaction A higher pressure means that there will be more particles of gas in the same volume. This will lead to more frequent collisions so the rate of reaction will increase. Describe and explain the effect of changes in the size of pieces of a reacting solid on the rate of reaction Smaller pieces of solid mean that the solid has a higher surface area. This means that more of the reactant particles are exposed so there are more frequent collisions. This increases the rate of reaction. Describe the characteristics of catalysts and their effect on rates of reaction A catalyst is a chemical which speeds up the rate of a reaction without being used up or altered itself. Catalysts are specific to the reaction, so a chemical that catalyses one reaction may not catalyse another reaction. Recall that enzymes act as catalysts in biological systems Enzymes are biological catalysts that up reactions in biological systems. Explain catalytic action in terms of activation energy A catalyst lowers the activation energy, which leads to more successful collisions. This increases the rate of reaction. Keywords: catalyse, catalyst, collide, directly proportional, enzyme, gas syringe, inversely proportional, pressure, rate of reaction, reaction time, successful collision, surface area
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