Chem definitions

Question 1

Isotopes

Answer 1

Atoms of the same element with same proton number but diff nucleon numbers

Question 2

Empirical formula

Answer 2

Chemical formula that shows the simplest ratio of atom in a compound

Question 3

Amphoteric property

Answer 3

A substance that shows both acidic and basic properties

Question 4

Alkali

Answer 4

A compound that produces OH- ions when it is dissolved in water

Question 5

Acid

Answer 5

A compound that produces H+ ions when it is dissolved in water

Question 6

Molarity

Answer 6

The number of moles of … Dissolved in 1 dm3 of the solution

Question 7

Diprotic acid

Answer 7

An acid that produces 2 mol of H+ ions for every mol of acid when it is dissolved in water

Question 8

Electrolyte

Answer 8

An ionic substance that can conduct electricity either in aqueous or molten state and can undergo chemical changes

Question 9

Weak acid

Answer 9

Dissociate partially in water to produce low conc of H+ ions

Question 10

Catalyst

Answer 10

A substance that can alter the rate of reaction while itself remain chemically unchanged at the end of the reaction

Question 11

Isomers

Answer 11

Compound with the same molecular formula, but with diff structural formulae

Question 12

Antioxidant

Answer 12

Prevent food from being oxidised on exposure to the air which will turn them into acids with an unpleasant smell

Question 13

Aspartame

Answer 13

Used to sweeten food

Question 14

Flavouring

Answer 14

Improve the taste or smell of food and restore taste loss due to food processing

Question 15

Msg

Answer 15

Bring out the flavours in many types of food

Question 16

Stabilisers

Answer 16

Help to mix two liquids that usually do not mic together so that they form an emulsion

Question 17

Thickeners

Answer 17

Substances that thicken food and give the food a firm, smooth and uniform texture

Question 18

Heat of combustion

Answer 18

The heat given out when one mole of a substance is completely burnt in excess of oxygen under standard conditions

Question 19

Food preservatives

Answer 19

A chemical that is added to food to retard the spoilage of food

Question 20

Vulcanisation

Answer 20

Process which makes the natural rubber harder and increases its elasticity by adding sulphur

Question 21

Redox reaction

Answer 21

Chemical reactions involving oxidation and reduction occuring simultaneously

Question 22

Heat of precipitation

Answer 22

The heat change when one mole of a precipitate is formed from their ions in aqueous solution

Question 23

Heat of displacement

Answer 23

The heat change when one mole of a metal is displaced from its salt solution by a more electropositive metal

Question 24

Heat of neutralisation

Answer 24

The heat change when one mole of water is formed from the reaction between an acid and an alkali

Question 25

Phenolphthalein

Answer 25

Used to determine the end point of the titration

Question 26

Proton number

Answer 26

Number of protons in the nucleus of an atom

Question 27

Nucleon number

Answer 27

Total number of proton and neutron in an atom

Question 28

Mole

Answer 28

Amount of substance that contain as many particle as the number of atoms is exactly 12g of carbon-12

Question 29

Molecular formula

Answer 29

The chemical formula which shows the exact number of atoms in a molecule

Question 30

Period

Answer 30

Horizontal row of elements in the Periodic Table of Elements

Question 31

Anion

Answer 31

A negatively charged ion

Question 32

Electrolysis

Answer 32

A process in which a compound js decomposed into its constituent elements by passing through an electric current through an electrolyte

Question 33

Cathode

Answer 33

The electrode which is connected to the negative terminal of the dry cell

Question 34

Alloy

Answer 34

An alloy is a mixture of two or more elements with a certain fixed composition in which the major components is a metal

Question 35

Polymer

Answer 35

Large molecules made up of many identical repeating subunits of monomer