A1: Halogens

Question 1

Halogens trend in reactivity

Answer 1

As you go down the table, reactivity decreases because shielding and atomic radium decrease, so nuclear attraction decreases, and it is less able to attract an electron for another species

Question 2

Appearance and state of F2 at RTP

Answer 2

Pale yellow gas

Question 3

Appearance and state of Cl2 at RTP

Answer 3

Pale green gas

Question 4

Appearance and state of Br2 at RTP

Answer 4

Red-brown liquid

Question 5

Appearance and state of I2 at RTP

Answer 5

Shiny grey-black solid

Question 6

Appearance and state of At2 at RTP

Answer 6

Never been seen

Question 7

Colour of Cl2 solution in water or cyclohexane

Answer 7

Pale green

Question 8

Colour of Br2 solution in water or cyclohexane

Answer 8

Orange

Question 9

Colour of I2 solution in water

Answer 9

Brown

Question 10

Colour of I2 solution in cyclohexane

Answer 10

Violet

Question 11

Define disproportionation

Answer 11

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

Question 12

Benefits of treating water with chlorine

Answer 12

Kills bacteria, making water safe to drink

Question 13

Risks of treating water with chlorine

Answer 13

Can cause formation of chlorinated hydrocarbons which are carcinogenic

Question 14

Cl2(aq)+H2O(l)

Answer 14

HClO(aq) + HCl(aq)

Question 15

Cl2(aq) + 2NaOH(aq) , where the NaOH is cold and dilute

Answer 15

NaClO(aq) + NaCl(aq) + H2O(l)

Question 16

What is in bleach

Answer 16

A high concentration of ClO-

Question 17

Cl- ion with silver nitrate

Answer 17

White precipitate, soluble in dilute ammonia

Question 18

Br- ion with silver nitrate

Answer 18

Cream precipitate, soluble in concentrated ammonia

Question 19

I- ion with silver nitrate

Answer 19

Yellow precipitate, insoluble in concentrated ammonia