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level: Level 1 of Chapter 9

Questions and Answers List

Rates of reactions

level questions: Level 1 of Chapter 9

QuestionAnswer
Increasing the temperature increases the rate of reaction because? (2)1. Increased energy results in particles moving around more quickly, which increases the frequency of collisions 2. Proportion of successful collisions increases because the proportion of particles exceeding the activation energy increases
Increasing the temperature increases the rate of reaction because? (2)1. Increased energy results in particles moving around more quickly, which increases the frequency of collisions 2. Proportion of successful collisions increases because the proportion of particles exceeding the activation energy increases
What is reaction kineticsThe study of rates of chemical reactions
What is the formula for rate of a chemical reactionchange in amount of reactants or products ➗ time
What is the units used for rate of reactionmol dm⁻³ s⁻¹
Rate of reaction usually changes as the reaction proceeds ,why?Because concentration of reactants is decreasing
What does the collision theory state?That in order to react with each other, particles must collide in correct orientation and with sufficient energy
What is ineffective collisionWhen reactant particles collide they mey simply bounce off each other, without changing
What is effective collisionIf particles do have enough energy to react, they may change into product particles when they collide
What is activation energy?The minimum energy that colliding particles must possess for a collision to be effective
According to collision theory, a reaction will speed up if:(2)1. Frequency of collisions increases 2. Proportion of particles with energy greater than the activation energy increases
What is frequency of collisionsnumber of collisions per unit time
What is a catalystA substance that increases the rate of a reaction but remains chemically unchanged itself at end of reaction
In reactions involving solutions, more concentrated reactants have a faster rate of reaction. Why?Because random motion of particles in solution results in more frequent collisions between reacting particles
Increasing the temperature increases the rate of reaction because? (2)1. Increased energy results in particles moving around more quickly, which increases the frequency of collisions 2. Proportion of successful collisions increases because the proportion of particles exceeding the activation energy increases
When a catalyst and the reactants in a catalysed reaction are in the same phase, we describe the catalyst as ...Homogeneous catalyst