Extent of chemical reactions

Question 1

Concentration-time graph

Answer 1

a graph of concentration versus time used to represent equilibrium reactions

Question 2

Dynamic equilibrium

Answer 2

the point in a reversible chemical reaction when the rate of the forward reaction is equal to the rate of the reverse reaction, and the concentrations of products and reactants are constant

Question 3

Equilibrium reaction

Answer 3

reaction in which reactants and products are constantly being formed

Question 4

Extent

Answer 4

the proportion of reactants that have been converted into products

Question 5

Irreversible reaction

Answer 5

a reaction that can only proceed in one direction and cannot be reversed

Question 6

Rate-time graph

Answer 6

a graph of rate of reaction versus time used to represent equilibrium reactions

Question 7

Reversible reaction

Answer 7

a reaction that can proceed both forwards and backwards

Question 8

Theoretical yield

Answer 8

the expected amount of product formed based on stoichiometric ratios and the mass of limiting reactant used

Question 9

Yield

Answer 9

the mass of product obtained during a chemical reaction

Question 10

Endothermic reaction

Answer 10

chemical reaction that absorbs energy (in the form of heat) from the surrounding environment

Question 11

Equilibrium constant (K)

Answer 11

the value of the concentration fraction for a system at equilibrium

Question 12

Equilibrium expression

Answer 12

K = [C]c[D]d / [A]a[B]b

Question 13

Equilibrium law

Answer 13

the value of K is the ratio of the concentrations of the products to the concentrations of the reactants i.e. K = [products] / [reactants]

Question 14

Exothermic reaction

Answer 14

chemical reaction accompanied by the release of energy (in the form of heat)

Question 15

Reaction quotient (Q)

Answer 15

the value of the concentration fraction for a system that is not at equilibrium

Question 16

Le Chatelier’s principle

Answer 16

when a system in dynamic equilibrium is subject to a change, the system will adjust itself to partially oppose the effect of the change

Question 17

Position of equilibrium

Answer 17

the relative concentrations of reactants and products at equilibrium for a given chemical reaction

Question 18

Compromise conditions

Answer 18

conditions that may not always give the greatest yield of product, but are the most economically viable when it comes to balancing factors like cost and rate of reaction

Question 19

Decarbonisation

Answer 19

the process of reducing or eliminating carbon dioxide and other greenhouse gas emissions from industrial processes

Question 20

Green hydrogen

Answer 20

hydrogen gas produced using renewable energy sources, such as wind or solar power, through electrolysis

Question 21

Grey hydrogen

Answer 21

hydrogen gas produced through steam methane reforming (SMR), a process that involves reacting natural gas with steam to produce hydrogen gas and carbon dioxide as a by-product

Question 22

Side reaction

Answer 22

a reaction that occurs at the same time as the main reaction, leading to the formation of side products and a lower yield of the main product