Unit 1/2 Exam Revision

Question 1

Groups

Answer 1

Column number indicated groups. Elements in the same column have the same number of electrons in the outer shell.

Question 2

Periods

Answer 2

Row number indicates periods. Elements found in the same row have the same number of electron occupied shells.

Question 3

Blocks

Answer 3

There are 4 different blocks in the periodic table. There is the S block, D block, P block and F block.
S block: Alkali and alkaline earth metals
D block: transition mental
P block: halogens, noble gases and metalloids
F block: lanthanides and actinides

Question 4

Group 1

Answer 4

Alkali metals – form ionic compounds, very reactive metals with oxygen and water, low electronegativities, powerful reactants (lose electrons), relatively soft metal.

Question 5

Group 2

Answer 5

Alkaline earth metals - form ionic compounds, reactive metals, low electronegativities, strong reactants.

Question 6

Group 17

Answer 6

Halogens – reactive non-metals, form ionic and covalent compounds, high electronegativities, powerful oxidants (gain electrons)

Question 7

Group 18

Answer 7

Noble gases – unreactive gases however a few compounds of krypton, xenon and radon have been made; outer shell contains 8 electrons except Helium.

Question 8

Naming ionic compounds

Answer 8

When a non-metal gains one or more electrons, the name of the negative ion ends in –ide. When a metal atom loses one or more electrons, the name of the positive ion is the same as that of the metal.

1. The first element (metal cation) in the formula is named in full
2. The second element is named as an anion. The name is shortened and given an –ide suffix.

Question 9

Intramolecular forces

Answer 9

Single covalent bond
Double covalent bond
Triple covalent bond

Question 10

Intermolecular forces

Answer 10

Dispersion forces -> every bond contains it
Hydrogen bonds -> Only occurs when hydrogen binds to either: F, O or N
Dipole – dipole -> When a hydrogen bond does not occur

Question 11

Naming covalent molecules

Answer 11

The first element remains the same but the second element gets the suffix of –ide. 
The first element gets a prefix unless there is only one molecule. The second element also gets a prefix:
Mono = 1
Di = 2
Tri = 3
Tetra = 4
Penta = 5
Hexa = 6
Hepta = 7
Octa = 8
Nona = 9
Deca = 10

Question 12

Isomers

Answer 12

Compounds with the same molecular formula by different structural formula

Question 13

Conjugate Acid/base pairs

Answer 13

Differ by one proton.
H3O+/ H2O
H2PO4-/ HPO42-

Question 14

Polyprotic acids

Answer 14

Have more than one proton to donate.

Question 15

Amphiprotic acids

Answer 15

it can either donate or accept a proton.

Question 16

Strong

Answer 16

The tendency to donate or accept a proton

Question 17

Weak

Answer 17

The tendency to donate or accept a proton

Question 18

Concentrated

Answer 18

Amount of original material added to water

Question 19

Dilute

Answer 19

Amount of original material added to water

Question 20

Spectator ions

Answer 20

any species that remains unchanged will be removed for the ionic equation.

Question 21

Solubility rules

Answer 21

1. all nitrates are soluble
2. all chlorides, bromides and iodides are soluble, except those of silver, lead and mercury
3. all sulfates are soluble, except those of barium, calcium and lead
4. all carbonates are insoluble, except those of Group 1 metals.
5. all hydroxides are insoluble, except those of Group 1 metals, barium and ammonium

Question 22

Primary standard

Answer 22

• It must be obtainable in very pure form
• It must have a known formula
• It must be stable; that is, its composition must not change over time due to the loss or gain of moisture or reaction with the air.
• Preferably, it should have a relatively high molar mass so that weighing errors are minimised.
• Preferably, it should be inexpensive.

Question 23

Secondary standard

Answer 23

Standard solutions may be prepared by dissolving a known mass of a primary standard in a known volume of solution.

Question 24

Endpoint

Answer 24

During a titration, the point at which the indicator changes colour is called the endpoint.

Question 25

Equivalance point

Answer 25

The point at which chemically equivalent amounts of acids and base have been added is called the equivalence point.