C8 Rates of reaction

Question 1

activation energy

Answer 1

the minimum energy needed for a reaction to take place

Question 2

anhydrous

Answer 2

describes a substance that does not contain water

Question 3

catalyst

Answer 3

a substance that speeds up a chemical reaction by providing a different pathway for the reaction that has a lower activation energy. The catalyst is chemically unchanged at the end of the reaction

Question 4

climate change

Answer 4

the change in global weather patterns that could be caused by excess levels of greenhouse gases in the atmosphere

Question 5

closed system

Answer 5

a system in which no matter enters or leaves

Question 6

collision theory

Answer 6

an explanation of chemical reactions in terms of reacting particles colliding with sufficient energy for a reaction to take place

Question 7

equilibrium

Answer 7

the point in a reversible reaction at which the forward and backward rates of reaction are the same. Therefore, the amounts of substances present in the reacting mixture remain constant

Question 8

hydrated

Answer 8

Describes a substance that contains water in its crystals

Question 9

Le Châtelier’s Principle

Answer 9

when a change in conditions is introduced to a system at equilibrium, the position of equilibrium shifts so as to cancel out the change

Question 10

precise / precision

Answer 10

a precise measurement is one in which there is very little spread about the mean value. Precision depends
only on the extent of random errors – it gives no indication of how close results are to the true (accurate) value

Question 11

reversible reaction

Answer 11

a reaction in which the products can re-form the reactants