chapter 8

Question 1

what is metallic bonding?

Answer 1

strong electrostatic attraction between metal cations and delocalised electrons

Question 2

what are the properties of metals?

Answer 2

high electrical conductivity when solid and molten
high melting and boiling points
insoluble

Question 3

what is the structure of simple molecular lattices?

Answer 3

strong covalent bonds between atoms in molecules
weak intermolecular forces between molecules

Question 4

what is the structure of giant covalent lattices?

Answer 4

atoms held together by network of strong covalent bonds

Question 5

whats the test for carbonates?

Answer 5

add dilute nitric acid
carbonates react to form CO2
if presents then bubbles of gas form

Question 6

whats the test for sulfates?

Answer 6

add barium nitrate
white precipitate forms (barium sulfate)

Question 7

what is the test for halide ions?

Answer 7

add silver nitrate solution

Question 8

what are the positive results for the halide test?

Answer 8

chlorine - white
bromine - cream
iodine - yellow

Question 9

what halide ion is soluble in dilute ammonia?

Answer 9

chlorine

Question 10

what halide ion is soluble in concentrated ammonia?

Answer 10

bromine

Question 11

what halide ion is not soluble in any ammonia?

Answer 11

iodine

Question 12

what is the order of tests to do?

Answer 12

carbonate
sulfate
halides
(silver carbonate or silver sulfate can form)

Question 13

what is the test for ammonia?

Answer 13

add aqueous sodium hydroxide
test gas released with moist pH paper
paper will turn blue

Question 14

what happens down the group for metal hydroxides (group 2)?

Answer 14

increases solubility
pH/alkalinity increases

Question 15

what is the trend down the group for halogens?

Answer 15

reactivity decreases
boiling point increases (increased strength of londons forces due to more electrons

Question 16

what does a halogen want to do in a reaction?

Answer 16

gain an electron
REDUCTION
oxidising agent

Question 17

what is the colour of chlorine in water?

Answer 17

pale green

Question 18

what is the colour of bromine in water?

Answer 18

orange

Question 19

what is the colour of iodine in water?

Answer 19

brown

Question 20

what is the colour of fluorine at RTP?

Answer 20

pale yellow gas

Question 21

what is the colour of chlorine at RTP?

Answer 21

pale green gas

Question 22

what is the colour of bromine at RTP?

Answer 22

red brown liquid

Question 23

what is the colour of iodine at RTP?

Answer 23

shiny grey-black solid

Question 24

what is the colour of chlorine when a non-polar solvent (e.g. cyclohexane) is added?

Answer 24

layer of pale green

Question 25

what is the colour of bromine when a non-polar solvent (e.g. cyclohexane) is added?

Answer 25

layer of orange

Question 26

what is the colour of iodine when a non-polar solvent (e.g. cyclohexane) is added?

Answer 26

layer of purple

Question 27

what is disproportionation?

Answer 27

redox reaction in which the same element is both oxidised and reduced

Question 28

what are the benefits of chlorine use?

Answer 28

kills bacteria present in water to make it safe to drink

Question 29

what are the risks of chlorine use?

Answer 29

extremely toxic gas
can react with water to form chlorinate hydrocarbons (suspected carcinogen)

Question 30

what agent are group 2 elements?

Answer 30

reducing agents as they gain 2 electrons

Question 31

what is the general equation for the reaction between group 2 elements and oxygen?

Answer 31

Mg (s) + 1/2 O2 (g) –> MgO (s)

Question 32

what do group 2 elements form when they react with water?

Answer 32

form an alkaline hydroxide
general formula = M(OH)2 and hydrogen gas

Question 33

what is the reactivity trend down the group of group 2 metals?

Answer 33

reactivity increases down the group

Question 34

what do group 2 elements form when reacting with a dilute acid?

Answer 34

salt and hydrogen
e.g. Mg + 2HCl –> MgCl2 + H2

Question 35

what do group 2 oxides do when they react with water?

Answer 35

release hydroxide ions

Question 36

what can group 2 elements be used for in real life?

Answer 36

calcium hydroxide added to fields to increase pH of acidic soils
medicine (e.g. indigestion tablets, antacids)