T3 Definitions (kapoor)

Question 1

Adsorption

Answer 1

The process that occurs when a gass liquid or solute is held to the surface of a solid or more rarely a liquid

Question 2

Boltzmann distribution

Answer 2

The distribution. Of energies of a molecules at a particular temperature, usually shown as a graph

Question 3

Catalyst

Answer 3

A substance that increases the rate of a chemical reaction. Without being used up in the process

Question 4

Dynamic equilibrium

Answer 4

The equilibrium that exists in a closed system when the rate of the forward reaction is equal to the rate of the reverse reaction

Question 5

Endothermic reaction

Answer 5

A reaction in which the enthalpy of the products is greater than the enthalpy of the reactants, resulting in heat being taken in from the surrounding

Question 6

Enthalpy

Answer 6

The heat content that is stored in a chemical system

Question 7

Standard enthalpy change of combustion

Answer 7

The enthalpy change that takes place when one mole of a substance reacts completely with oxygen under standard conditions, all reactants and products being in their standard states.

Question 8

Standard enthalpy change of formation

Answer 8

The enthalpy change that takes place when one mole of a compound is formed from its constituent elements in their standard states under standard conditions.

Question 9

Standard enthalpy change of reaction

Answer 9

The enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactants and products being in their standard states.

Question 10

Enthalpy cycle

Answer 10

A diagram showing alternative routes between reactants and products which allows the indirect determination of an enthalpy change from other known enthalpy changes using Hess’ law.

Question 11

Enthalpy profile diagram

Answer 11

A diagram for the reaction to complacency the enthalpy of the reactants with the enthalpy of yhe products

Question 12

Hess law

Answer 12

If a reaction can task place by more than one route and the initial and final conditions are the same, the total enthalpy chmage is the same for each route

Question 13

Heterogeneous catalyst

Answer 13

A reaction in which the catalyst gas a differnt physical state for the reactants, frequently, reactants are gases whilst the catalysts is a solid

Question 14

Homogenous catalysis

Answer 14

A reaction in which the catalysts and reactants are in the same physical state whichh is most frequently the aqueous or gaseous state

Question 15

Second ionisation energy

Answer 15

The energy required to remove one electron from each ion in one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions.

Question 16

Successive ionisatio. Energy

Answer 16

A measure of the energy required to remove each electrons in turn

Question 17

Kc

Answer 17

equilibrium constant us3d to predict position of equilibrium

Question 18

Le chateliers principle

Answer 18

When a system in dynamic equilibrium is subjected to a change the position of equilibrium will shift to minimise the change

Question 19

Periodicity

Answer 19

A regular periodic variation of properties of elements with atomic number and position in the periodic table

Question 20

Rate of reaction

Answer 20

The change in concentration of a reactant or a product in a given time

Question 21

Specific heat capacity

Answer 21

The energy required to raise the temperature of 1b of a substance by 1°c

Question 22

Standard condition s

Answer 22

A pressure of 100kpa, a stated temperature, (298K)
Conc 1 mol dm-3

Question 23

Acid

Answer 23

A species that is a proton donor

Question 24

Alkali

Answer 24

A type of base that dissolves in water forming hydroxide ions

Question 25

Base

Answer 25

Species that is a proton acceptor

Question 26

Disproportionation

Answer 26

The oxidation and reduction of the same element in a redox reaction

Question 27

Mole

Answer 27

The amount of any substance containing ad man particles as there are n exactly 12g of carbon12

Question 28

Oxidising agent

Answer 28

A reagent that oxides another species

Question 29

Reducing agent

Answer 29

A reagent that reduces another species

Question 30

Salt

Answer 30

A chemical compound formed form an acid, when a H+ form the acid has been replaced by a metal ion or another positive ions, such as the ammonium ion NH4+