The Halogens

Question 1

State one risk of using chlorine to sterilise water

Answer 1

Chlorine in water can react with organic compounds to form chlorinated hydrocarbons, which can cause cancer

Question 2

What is the trend in Boiling Point as you go down Group 7? Why?

Answer 2

•Boiling Point Increases
•Size of atom increases, meaning there are more electrons
•There are more London forces between the molecules that need to be broken

Question 3

What is the trend in oxidising power as you go down Group 7?

Answer 3

•Oxidising Power decreases as they become less reactive
•Atomic Radius increases
•Shielding increases
•Weaker Attraction on outer electron

Question 4

What is the reagent, observations and simplest ionic equation when testing for sulfate ions?

Answer 4

•Reagent: Barium Nitrate
•Observations: White PPT
•Ionic Equation: Ba(2+) + SO4(2-) -> BaSO4

Question 5

What is the reagent, observations and simplest ionic equation when testing for carbonate ions?

Answer 5

•Reagent: Nitric Acid
•Observations: Fizzing
•Ionic Equation: 2H(+) + CO3(2-) -> H2O + CO2

Question 6

What are the observations of iodide ions in : i)Dilute NH3 ii)Concentrated NH3?

Answer 6

i) No Visible Change
ii) No Visible Change

Question 7

What are the observations of bromide ions in i) Dilute NH3 ii) Concentrated NH3?

Answer 7

i) PPT partially dissolves
ii) PPT dissolves

Question 8

What are the observations of chloride ions in i) Dilute NH3 ii) Concentrated NH3?

Answer 8

i) PPT dissolves
ii) PPT dissolves

Question 9

What are the observations of fluoride ions in i) Dilute NH3 ii) Concentrated NH3?

Answer 9

i) No Visible Change
ii) No Visible Change

Question 10

What is the correct sequence of testing for ions?

Answer 10

1)Carbonate
2)Sulfate
3)Halide

Question 11

What is disproportionation?

Answer 11

Oxidation and Reduction of the same element

Question 12

What is the reagent, observations and simplest ionic equation when testing for ammonium ions?

Answer 12

Reagent: Aqueous Sodium Hydroxide
Observations: Damp Litmus Paper turns Blue
Ionic Equation: NH4(+) + OH(-) -> NH3 + H2O

Question 13

What is the reagent, observations and simplest ionic equation when testing for chloride ions?

Answer 13

Reagent: Acidfied Silver Nitrate
Observations: White PPT formed
Ionic Equation: Ag(+) + Cl(-) -> AgCl

Question 14

What are the reagent, observations and simplest ionic equation when testing for bromide ions?

Answer 14

Reagent: Acidified Silver Nitrate
Observations: Cream PPT formed
Ionic Equation: Ag(+) + Br(-) -> AgBr

Question 15

What are the reagent, observations and simplest ionic equation when testing for iodide ions?

Answer 15

Reagent: Acidifed Silver Nitrate
Observations: Yellow PPT formed
Ionic Equation: Ag(+) + I(-) -> AgI