C3.1

Question 1

What can the formulae of metals be written as

Answer 1

Metals are always written empirically as they exist in giant metallic lattices

Question 2

What do the non-metals in group 0 exist as

Answer 2

They exist as individual atoms, attracted to each other by weak intermolecular forces.

Question 3

What is a diatomic molecule

Answer 3

A diatomic molecule contains two atoms covalently bonded. An example is CL2.

Question 4

What do phosphorus and sulphur exist as

Answer 4

P4 and S8

Question 5

What does the molecular formula for a simple covalent structure contain

Answer 5

.The symbols for each element it contains
.The number of atoms of each element in one of its molecule

Question 6

What do the metals in group 1,2,3 produce ions of

Answer 6

They produce positive ions of which the charge is the same number as their group.

Question 7

What ions do transitional metals form

Answer 7

They form 2+ ions.

Question 8

What do metals in group 5,6,7 produce ions of

Answer 8

They produce negative ions in which the number of charges = 8 - group number

Question 9

Formula of different compound ions

Answer 9

ammonium NH4+
silver Ag+
Barium Ba2+
Copper (||) Cu2+
Iron (||) Fe2+
Lead (||) Pb2+
Zinc Zn2+
Aluminium Al3+
Iron Fe3+
Hydroxide OH-
Nitrate NO3-
Carbonate CO3 2-
Sulfate SO4 2-

Question 10

Law of conservation of mass

Answer 10

Atoms can’t be created or destroyed in a chemical reaction.

Question 11

How can you investigate the law of conservation of mass

Answer 11

You can investigate conservation of mass in a closed system
. a beaker of reactants in a solution where the products are not gases
. A flask attached to a gas syringe to stop products in the gas state from escaping

Question 12

Why would there be a decrease in mass in a reaction

Answer 12

Substances can leave or enter the reaction mixture in a non-enclosed system. This usually happens when the reaction involves a gas. For example if a gas is produced it will escape causing a decrease in mass. It can also appear to go up if reacts with air.

Question 13

What does a balanced equation show

Answer 13

.How atoms are rearranged in a reaction
.The relative amount of each substance

Question 14

When is an an equation balanced

Answer 14

When there an equal number of atoms of each element on both side of the equation.

Question 15

Different state symbols

Answer 15

(s) - solid
(l) - liquid
(aq) - aqueous
(g) - gas

Question 16

What is a half equation

Answer 16

A half equation is a model for the change that happens to one reactant in a chemical reaction.

Question 17

Example of a half equation

Answer 17

Na -> Na+ + e-

Question 18

What must you do in half equations

Answer 18

Balance the charges

Question 19

What does an ionic equation show

Answer 19

It shows the ions present in a reaction mixture. It usually also includes the formulae of any ionic substances present.

Question 20

What are spectator ions

Answer 20

They are in the reaction mixture but don’t take part in the reaction.

Question 21

What is the mole

Answer 21

The mole is the amount of any substance that contains the same number of entities as there are in 12g of carbon -12 atoms.

Question 22

Mole formula

Answer 22

Mole = Mass/molar mass (mr)