Group 7

Question 1

F2

Answer 1

Yellow gas

Toxic

Very reactive

Question 2

Cl2

Answer 2

Green gas

Toxic

Very reactive

Question 3

Br2

Answer 3

Orange liquid

Very reactive

Toxic
Used with water

Question 4

I2

Answer 4

Grey crystals
Reactive
Toxic
Turns into purple vapour(heat)
Solution-antiseptic(brown)

Question 5

Atomic radius trend

Answer 5

Increases going down
More shells
Greater shielding
Weaker attraction to nucleus

Question 6

Electronegativity trend

Answer 6

Decreases going down
Greater atomic radius
Less attraction to nucleus

Question 7

Mp trend

Answer 7

-Increases down group.
-Molecules become larger, more
e- + larger vdw.
-More energy required to break vdw.

Question 8

Ionisation energy trend

Answer 8

Going down decreases
More shells greater shielding
Less energy needed

Question 9

Oxidising agent

Answer 9

Electron acceptor

Question 10

Reducing agent

Answer 10

Electron donor

Question 11

Hallide trend x-

Answer 11

Going down
Becomes stronger reducing agent
More shells
More shielding
E- further from nucleus

Question 12

Halogen trend x2

Answer 12

Strong to weak oxidising agent going down
Strong oxidising agent
To weak

Question 13

Bleach equation

Answer 13

2NaOH + Cl2–>NaClO + NaCl + H2O
Disproportionation

Question 14

Bromide plus chlorine

Answer 14

Cl2 + 2Br- ~ 2cl- + Br2
Yellow solution
Displacement

Question 15

Iodide plus chlorine

Answer 15

Cl2 + 2I- ~ 2cl- + I2

Question 16

Bromine plus iodide

Answer 16

2Br- + I2 ~ Br2 + 2I-
Brown solution

Question 17

the equation to show the displacement reaction between NaCl and H2S04 and state any observations.

Answer 17

-NaCI(s) + H2S04(1) -> HCI(g) + NaHSO4(S)
-White steamy fumes.

Question 18

the equation to show the displacement reaction between NaF and H2SO4 and state any observations.

Answer 18

-NaF(s) + H2SO4(1) -> HF(g)
+NaHSO4(s)
-White steamy fumes.

Question 19

the equation to show the redox reaction between NaBr and H2O4 and state any observations.

Answer 19

Red: 2H+ + H2S04 + 2e- -> SO2 +
2H20
Ox: 2Br- -> Br2 + 2e-Redox:
2H+ + H2SO4 + 2Br- -> SO2 + 2H20
+ Br2
-brown liquid/orangey brown
fumes(Br2)
- Colourless acidic gas (SO2)

Question 20

the equation to
show the redox reaction
between Nal and H2SO4
and state any
observations.

Answer 20

Red: 2H+ + H2S04 + 2e- -> SO2 +
2H20
6H+ + H2504 + 6e- -> S + 4H20
8H+ + H2S04 + 8e- -> H2S + 4H20
Ox: 12–> 12 + 2e-
Redox: 6H+ + H2S04 + 61- -> S +
4H20 + 312
8H+ + H2504 + 81- -> H2S + 4H20 +
412
-Yellow solid (S)
-Rotten egg smell (H2S)
-Grey/black solid (12)

Question 21

Testing for corrosive product

Answer 21

Blue litmus paper turns red then bleaches.

Question 22

the equation to show the redox reaction between Ag+ and Cl- and state any observations.

Answer 22

-Ag+ (aq) + Cl-(aq) -> AgCI(s)
-White ppt

Question 23

Does silver chloride dissolve in dilute or conc.
ammonia?

Answer 23

Dilute ammonia to form a complex ion.

Question 24

the equation to
show the redox reaction between Ag+ and Br- and state any observations.

Answer 24

-Ag+(aq) + Br- (ag) -> AgBr(s)
-Cream ppt

Question 25

Does silver bromide dissolve in dilute or conc. ammonia?

Answer 25

Conc. ammonia to form a complex ion.

Question 26

the equation to show the redox reaction between Ag+ and I- and state any observations.

Answer 26

-Ag+(aq) + I-(aq) -> Agl(s) -Pale yellow ppt

Question 27

Does silver iodine dissolve in dilute or conc. ammonia?

Answer 27

Neither, it is insoluble in ammonia.

Question 28

Write the equation to show the disproportionation reaction between Cl2 and H20 and state any observations.

Answer 28

-CI2(g) + H20(l) = HCIO(ag) + HCl(ag) -CI2 greenish colour -HCIO is bleach

Question 29

Write the equation to show the disproportionation reaction between Cl2 and H2O in UV and state any observations.

Answer 29

2C12 + 2H20 -> 4H+ + 4C1- + 02

Question 30

Write the equation to show the disproportionation reaction between CI2 and cold dilute NaOH and state any observations.

Answer 30

-CI2(ag) + 2NaOH(aq) -> NaC(ag) + NaCIO(ag) + H20(l) -Cl2 (+Br2, 12) reacts and the colour fades to colourless. -NaCI + NaCIO used as bleach.