Definitions

Question 1

Empirical Formula

Answer 1

Lowest whole number ratio of the elements in a compound

Question 2

Molecular Formula

Answer 2

A formula that shows the actual number of atoms of each element presented in one molecule of a compound

Question 3

Molar Ratio

Answer 3

Ratio in reactants and in a chemical reaction, react

Question 4

Limiting Reactant

Answer 4

A reactant that is completely used up in a chemical reaction

Question 5

Law of conservation of mass

Answer 5

Total mass of reactant= Total mass of products

Question 6

Ideal Gas

Answer 6

A gas where gas particles are independent

Question 7

Experimental Yield

Answer 7

Amount of product made during the experiment

Question 8

Solution

Answer 8

A homogeneous mixture of a solute in a solvent

Question 9

Solute

Answer 9

The dissolved component of a solution

Question 10

Avogadro’s Law

Answer 10

Equal volume of gases at the same temperature and pressure contain equal number of particles

Question 11

Avogadro’s Constant

Answer 11

The amount of particles in one mole of a substance. 6.02x10^23

Question 12

Percentage Yield

Answer 12

A calculation of the experimental yield as a percentage of the theoretical yield

Question 13

Reactant in Excess

Answer 13

A reactant that may not be completely used up

Question 14

Relative molecular mass

Answer 14

The sum of the relative atomic mass of the the elements as given in the molecular formula of a compound

Question 15

State Symbols

Answer 15

Symbols use in chemical equations to indicate state

Question 16

Mole

Answer 16

The amount of substance containing the same amount of particles as there are atoms

Question 17

Relative formula mass

Answer 17

The sum of the relative atomic mass of the elements given in a formula of an non-molecular compound

Question 18

Standard
Temperature &
Pressure

Answer 18

A set of conditions applied to gaseous calculations

Question 19

Theoretical Yield

Answer 19

The amount of product that is expected to be produced in a chemical reaction, based on 100% reactions of reactant

Question 20

Molar volume

Answer 20

The volume occupied by one mole in STP

Question 21

Relative atomic mass

Answer 21

The weighed mean of the masses of the naturally occurring isotopes of the elements

Question 22

Percentage composition

Answer 22

Amount of each element Ina compound expressed as a percentage

Question 23

Solvent

Answer 23

A substance, usually a liquid, that is able to dissolve another substance, a solute

Question 24

Concentration

Answer 24

Amount of solute in a given volume of solution

Question 25

Molar mass

Answer 25

The mass of one mole of a substance

Question 26

Nuclear Charge

Answer 26

The effective nuclear charge is the net positive charge experienced by valence electrons.

Question 27

Isotopes

Answer 27

an atom of a given element may have a wide range in its number of neutrons. The number of nucleons (both protons and neutrons) in the nucleus is the atom's mass number, and each isotope of a given element has a different mass number.

Question 28

Ionization Energy

Answer 28

The ionization energy is qualitatively defined as the amount of energy required to remove the most loosely bound electron of an isolated gaseous atom to form a cation.

Question 29

Electronegativity

Answer 29

Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons.

Question 30

Electron Affinity

Answer 30

Electron affinity is defined as the change in energy of a neutral atom (gas) when an electron is added to the atom to form a negative ion. In other words, the neutral atom's likelihood of gaining an electron.

Question 31

Atomic Radius

Answer 31

The atomic radius of a chemical element is a measure of the size of its atoms

Question 32

Ionic Radius

Answer 32

Ionic radius is the radius of an atom's ion.

Question 33

Ligands

Answer 33

Ligands act as Lewis bases (electron pair donors), and the central atom acts as a Lewis acid (electron pair acceptor).

Question 34

Complex Ions

Answer 34

A complex ion has a metal ion at its centre with a number of other molecules or ions surrounding it. These can be considered to be attached to the central ion by co-ordinate (dative covalent) bonds.

Question 35

Activation energy

Answer 35

The energy required to break the bonds of the reactants and hence allow a reaction to take place

Question 36

Average bond enthalpy

Answer 36

The amount of energy required to break one mole of bonds averaged across a range of compounds containing that bond

Question 37

Combustion reaction

Answer 37

an exothermic reaction in which a fuel is oxidized by oxygen

Question 38

Endothermic reaction

Answer 38

A reaction that absorbs heat energy from surroundings

Question 39

Enthalpy

Answer 39

The energy or heat energy content of a substance

Question 40

Exothermic reaction

Answer 40

A reaction that releases heat energy to surroundings

Question 41

Hess's Law

Answer 41

a law which states that the heat evolved or absorbed in a chemical process is the same, whether the process takes place in one or in several ways