Chapter C8 Rates And Equilibrium Flashcards
What is the rate of a chemical reaction?
How fast reactants turn into products
What are the three techniques used to work out the rate of reaction?
Measuring decreasing mass of a reaction mixture
Measuring the increasing volume of gas given off
Measuring the decreasing light passing through a solution
Five main factors that affect reaction rate
Temperature Surface area of solid Concentration of solutions Pressure of gases Catalyst
What is collision theory?
An explanation of chemical reactions in terms of reacting particles colliding with sufficient energy for a reaction to take place
What is activation energy?
The minimum amount of energy particles need before they can react
Why does raiding the temperature increase reaction time?
Particles collide more often
Particles collide with more energy
What does increasing pressure of reacting gases also increase?
Frequency of collisions/ rate of reaction
What is a catalyst?
Substance that changes the rate of reaction
How do catalysts work?
Provide an alternative reaction path to the products with a lower activation energy than the reaction without the catalyst present- a higher proportion of the reactant particles have sufficient energy to react
Advantages of using a catalyst?
Saves money and the environment (less fossil fuels required)
Does a catalyst get used up in a reaction?
No
What symbol is used to show reversible reactions?
Half arrows
Do reversible reactions lose or gain energy?
No- one reaction will be either exothermic or endothermic, and the opposite will be the other
What is a closed system?
A system in which no matter enters or leaves
What is equilibrium?
The rate of the forward reaction equals the rate of the reverse reaction?
