3.2.6 Reactions of Ions in Aqueous Solution

Question 1

What is the aqueous ion of iron (II)?

What is its colour?

Answer 1

[ Fe (H2O)6 ] 2+

Green solution

Question 2

What is the aqueous ion of copper (II)?

What is its colour?

Answer 2

[ Cu (H2O)6 ] 2+

Blue solution

Question 3

What is the aqueous ion of iron (III)?

What is its colour?

Answer 3

[ Fe (H2O)6 ] 3+

Purple solution

Question 4

What is the aqueous ion of aluminium (III)?

What is its colour?

Answer 4

[ Al (H2O)6 ] 3+

Colourless

Question 5

What is the action of aqueous NaOH or NH3 on iron (II)?

Answer 5

Fe (H2O)4 (OH)2 (s)

Green precipitate

Question 6

What is the action of aqueous NaOH or NH3 on copper (II)?

Answer 6

Cu (H2O)4 (OH)2 (s)

Blue precipitate

Question 7

What is the action of aqueous NaOH or NH3 on iron (III)?

Answer 7

Fe (H2O)3 (OH)3 (s)

Brown precipitate

Question 8

What is the action of aqueous NaOH or NH3 on aluminium (III)?

Answer 8

Al (H2O)3 (OH)3 (s)

White precipitate

Question 9

What ions are affected by an excess of NaOH?

Answer 9

Aluminium (III)
[ Al (OH)4 ]-
Colourless solution

Question 10

What ions are affected by an excess of NH3?

Answer 10

Copper (II)
[ Cu (H2O)2 (NH3)4 ] 2+
Deep blue solution

Question 11

What is the effect of Na2CO3 on iron (II)?

Answer 11

FeCO3

Green precipitate

Question 12

What is the effect of Na2CO3 on copper (II)?

Answer 12

CuCO3

Blue - green precipitate

Question 13

What is the effect of Na2CO3 on iron (III)?

Answer 13

Fe (H2O)3 (OH)3

Brown precipitate and CO2 gas evolved

Question 14

What is the effect of Na2CO3 on aluminium (III)?

Answer 14

Al (H2O)3 (OH)3

White precipitate and CO2 gas evolved

Question 15

What are the four ions of vanadium caused by reduction?

Answer 15

V(V), V(IV), V(III) and V(II)

Question 16

What is the species of V(V) in acidic solution? What is the colour?

Answer 16

[ VO2 (H2O)4 ]+

Yellow

Question 17

What is the species of V(IV) in acidic solution? What is the colour?

Answer 17

[ VO (H2O)5 ] 2+

Blue

Question 18

What is the species of V(III) in acidic solution? What is the colour?

Answer 18

[ V (H2O)6 ] 3+

Green

Question 19

What is the species of V(II) in acidic solution? What is the colour?

Answer 19

[ V (H2O)6 ] 2+

Purple

Question 20

What colours do Fe (III) compounds produce?

Answer 20

Purple or brown

Question 21

What colours do Fe (II) compounds produce?

Answer 21

Green

Question 22

What colours do copper (II) compounds produce?

Answer 22

Blue or blue-green

Question 23

What colours do aluminium (III) compounds produce?

Answer 23

Colourless or white

Question 24

What are the colours of vanadium ions in solution?

Answer 24

5: Yellow
4: Blue
3: Green
2: Purple