Group 17

Question 1

Colour of F2

Answer 1

Pale Yellow gas

Question 2

Colour of Cl2

Answer 2

Green Gas

Question 3

Colour of Br2

Answer 3

Dark Orange liquid

Question 4

colour of I2

Answer 4

Black solid / purple vapour

Question 5

Definition of volatility

Answer 5

How easily a substance can evaporate

Question 6

Trends in boiling point and melting point of group 17 elements

Answer 6

Boiling point and melting points increases down the group as number of electrons increase in each element which causes stronger induced dipole force

Question 7

Trend in bond strength down group 17

Answer 7

Decreases down the group as higher atomic radius which caused the attraction between outer electrons and the nucleus to decrease

Question 8

Definition of bond ethalpy

Answer 8

Energy required to break one mole of bond in gaseous state

Question 9

Trends in bond enthalpy going down group 17
- talk about fluorine

Answer 9

Overall decrease as atomic radius increases. Fluorine has a lower bond enthalpy than chlorine and bromine as it is so small that the lone pairs cause repulsion from each other

Question 10

How do halogens react with metal

Answer 10

They accept an electron from the metal. Therefore halogens are oxidising agents.

Question 11

Trends in oxidising power of halogen

Answer 11

Decreases down the group as electronegativity decreases down the group
- Chlorine is very hard to get oxidized, only f2, kmno4, k2cr2O7
- Impossible for fluorine to get oxidized

Question 12

Observation of fluorine reacting with hydrogen

Answer 12

Reacts explosively, even in cool/ dark conditions

Question 13

Observation of chlorine reacting with hydrogen

Answer 13

Reacts explosively in sunlight

Question 14

Observation of bromine reacting with hydrogen

Answer 14

Reacts slowly on heating

Question 15

Observation of iodine reacting with hydrogen

Answer 15

slow and forms an equilibrium mixture on heating

Question 16

Thermal Stability definition

Answer 16

How well a substance can resist breaking down when heated

Question 17

Trends in thermal stability going down the group

Answer 17

Decreases down the group as atomic radius increases which causes weaker bond. Bond length increases which caused it to be weak.

Question 18

Trends in Reducing power of halide ions down the group

Answer 18

Increases down the group as ionic radius increases which caused the electrostatic attraction to be weaker

Question 19

How can halide ions be identified in an unknown solution

Answer 19

Add silver nitrate followed by ammonia solution

Question 20

General equation of silver nitrate + halogen

Answer 20

AgNO3(aq) + X⁻ (aq) –> AgX(s) + NO3⁻ (aq)

Question 21

Colour of silver chloride ppt

Answer 21

White

Question 22

Colour of silver bromide ppt

Answer 22

Cream

Question 23

Colour of silver iodide ppt

Answer 23

Yellow

Question 24

General equation of sulfuric acid + Halide ion

Answer 24

H2SO4(l) + X⁻(aq) –> HX (g) + HSO4⁻ (aq)

Question 25

Solubility of silver chloride in dilute and conc ammonia solution

Answer 25

Soluble in both

Question 26

Solubility of silver bromide in dilute and conc ammonia solution

Answer 26

insoluble in dilute ammonia solution but soluble in conc ammonia solution

Question 27

Solubility of silver iodide in dilute and conc ammonia solution

Answer 27

Insoluble in neither dilute nor conc ammonia solution

Question 28

H2SO4 (aq) + NaCl (s) --> Observation

Answer 28

H2SO4 (aq) + NaCl (s) --> HCl (g) + NaHSO4 (aq) - White fumes of HCl gas

Question 29

H2SO4 (aq) + NaBr(s) -->

Answer 29

H2SO4 (aq) + NaBr(s) --> HBr (g) + NaHSO4 (aq)

Question 30

HBr (g) + H2SO4 (l) → Observation

Answer 30

HBr (g) + H2SO4 (l) → Br2 (g) + SO2 (g) + H2O (l) Reddish brown Br2 gas

Question 31

H2SO4 (aq) + NaI (s) →

Answer 31

H2SO4 (aq) + NaI (s) → HI (g) + NaHSO4 (aq)

Question 32

H2SO4 (aq) + 2HI (s) → Observations:

Answer 32

H2SO4 (aq) + 2HI (s) → I2 (g) + SO2 (g) + 2H2O (l) Violet I2 vopour

Question 33

H2SO4 (aq) + 6HI (s) → Observations

Answer 33

H2SO4 (aq) + 6HI (s) → I2 (g) + S (s) + H2O (l) Yellow solid of S

Question 34

H2SO4 (aq) + 8HI (s) → Observations:

Answer 34

H2SO4 (aq) + 8HI (s) → I2 (g) + H2S (s) + H2O (l) Bad egg smell of H2S

Question 35

equation of chlorine in cold NaOH (alkaline)

Answer 35

Cl2 (aq) + 2NaOH (aq) → NaCl (aq) + NaClO (aq) + H2O (l)

Question 36

equation of chlorine in hot NaOH (alkaline)

Answer 36

Cl2 (aq) + NaOH (aq) → NaCl (aq) + NaClO3 (aq) + H2O (l)

Question 37

equation of chlorine in water

Answer 37

Cl2 (aq) + H2O (l) → HCl (aq) + HClO (aq)

Question 38

NaClO + HCl —>

Answer 38

NaClO + HCl —> NaCl + Cl2 + H2O