4: Inorganic - Halogens

Question 1

Fluorine gas colour

Answer 1

Pale yellow

Question 2

Chlorine gas colour

Answer 2

Green

Question 3

Bromine liquid colour

Answer 3

Red-brown

Question 4

Iodine solid colour

Answer 4

Grey

Question 5

Chlorine water colour

Answer 5

Virtually colourless

Question 6

Bromine water colour

Answer 6

Yellow/ orange

Question 7

Iodine water colour

Answer 7

Brown

Question 8

Bromine in hexane colour

Answer 8

Orange/ red

Question 9

Iodine in hexane colour

Answer 9

Pink/ violet

Question 10

Chlorine + Cold sodium hydroxide

Answer 10

NaClO + NaCl + H₂O

Question 11

Chlorine + Hot sodium hydroxide

Answer 11

NaClO3 + 5NaCl + 3H₂O

Question 12

Bleach

Answer 12

Sodium chlorate (I) solution - NaClO

Question 13

Bleach uses

Answer 13

Water treatment, to bleach paper and textiles, cleaning

Question 14

Chlorine + Water

Answer 14

Disproportionation
Equilibrium
HCl + HClO

Question 15

Which ions kill bacteria?

Answer 15

Chlorate (I) ions
ClO-

Question 16

KF + H2SO4

Answer 16

HF + KHSO4
Not redox
Fluoride ions isn’t a strong enough reducing agent to reduce the sulfuric acid

Question 17

KCl + H2SO4

Answer 17

HCl + KHSO4
Not redox

Question 18

KBr + H2SO4

Answer 18

HBr + KHSO4
2HBr + H2SO4 —> Br2 + SO2 + 2H2O

Question 19

KBr + H2SO4 observations

Answer 19

choking fumes of SO2
Orange fumes of Br2

Question 20

KI + H2SO4

Answer 20

KHSO4 + HI
2HI + H2SO4 —> I2 + SO2 + 2H2O
6HI + SO2 —> H2S + 3I2 + 2H2O

Question 21

KI + H2SO4 observations

Answer 21

H2S is toxic and smells of rotten eggs
Choking fumes of SO2