1.the periodic table

Question 1

Colour of Chlorine in water(polar) and cyclohexane(non-polar)

Answer 1

colourless in polar water colourless in non-polar cyclohexane

Question 2

Colour of Bromine in water(polar) and cyclohexane(non-polar)

Answer 2

yellow-orange in polar water yellow-orange in non-polar cyclohexane

Question 3

Colour of Iodine in water(polar) and cyclohexane(non-polar)

Answer 3

brown in polar water purple in non-polar cyclohexane

Question 4

Most powerful group 7 O.A

Answer 4

F2 is the most powerful and so on they can oxidise lower reactivity halide ions

Question 5

colours and states of the pure halides

Answer 5

F2- pale yellow gas CL2- dense green gas Br2- orange/brown liquid (same as a gas) I2- dark grey sold (purple gas)

Question 6

Reactivity series in group 7 and why.

Answer 6

Reactivity decreases down the group. As to form ions they have to gain 1e- and the ionic radi are smaller for the higher up atoms which means e- are more strongly attracted to it. SHieldiung e- and neuclear charge cancel out.

Question 7

Why is the ionic radis bigger in halogens then the atomic radius?

Answer 7

The ions are larger because the repulsion added when all the orbitals are full expands the radius .

Question 8

what does isoelectronic mean

Answer 8

same number of valence e-

Question 9

disproportination

Answer 9

when the same element gets simultaneously oxidised and reduced in a reaction.

Question 10

Form a compound that is a disinfectant for pools, drinking water use….

Answer 10

NaOH + Cl not water +CL

Question 11

Cold!!! forming a disinfectant equation.

Answer 11

Cl₂+ 2NaOH –> NaCL + NaClO + H₂O

Question 12

hot!!! forming a disinfectant equation.

Answer 12

3Cl₂+ 6NaOH –> 5NaCL + NaClO₃ + 3H₂O

Question 13

Cl₂+H₂O–>

Answer 13

HCl + HClO

Question 14

What colour are group 1&2 compounds

What colour are group 1&2 solutions

Answer 14

compounds - white

solutions - coulourless

Question 15

Group 2 reactivity

Answer 15

increases as you go down the group, becuas eto react they need to lose e-

Atomic radius increase which decreses attraction and makes it easier to lose e- . SHieldiung e- and neuclear charge cancel out

Question 16

Thermal decompostion of group 2 carbonates

Answer 16

MCO₃ –> CO₂ + MO

CO₂ testing with limewater

( Ca(OH)₂+CO₂–>CaCO₃)

Question 17

Group 2 thermal decomposition order and why.

Answer 17

Easy-MgCO₃ Gets harder down the group becuase they are more thermally stable and are harder to decompose.

Question 18

Uses of the group 2 hydroxides Ca(OH)₂ and Mg(OH)₂

Answer 18

Ca(OH)₂ - is used by farmers and garderners as ‘lime’ to neutralise acid soils.

Mg(OH)₂- is used in ‘milk of magnesia’ in order to relieve indigestion, it nutralises excess stomach acid.

Question 19

Group 2 oxides and hydroxides are….

Answer 19

bases…. they are neutralised by acids to form a salt and water.

Question 20

soulubilty trend in group 2 hydroxides

Answer 20

they become more soluble down the group, this means lower down metal hydoxides make a more alkali solution.

Question 21

Halide ions with silver nitrate solution.

Answer 21

chloride ions-White (goes coulourless in all ammonia)

Bromide ions- Cream (goes coulourless in conc ammonia)

Iodide ions- Yellow

Question 22

Group 2 metal + water

Answer 22

M + 2H₂O–> M(OH)₂+H₂

Question 23

uses of ionic halide compounds.

Answer 23

NaCl-common salt

NaF(and tin fluoride) added to toothpaste to prevent decay.

CaF₂ crystals useds to make lenses that focus infrared light.

Question 24

What is a disadvantage to using chlorine in water treatment.

Answer 24

chlorine is toxic/poisonous and could form chlorinated hydrocarbons (carcinogens)

Question 25

Define periodicity

Answer 25

a repeating pattern of properties shown across different periods.