3.2.6 Reactions of Ions in Aqueous Solution

Question 1

What coulour is aqueous [Fe(H2O)6]2+

Answer 1

Green solution

Question 2

What happens to aqueous [Fe(H2O)6]2+ when NaOH is added?

Answer 2

Green solution forms green precipitate
(goes brown on standing in air)

Question 3

What happens to aqueous [Fe(H2O)6]3+ when NaOH is added?

Answer 3

Brown solution forms brown precipitate

Question 4

What happens to aqueous [Al(H2O)6]3+ when NaOH is added?

Answer 4

Colourless solution forms white precipitate

Question 5

What happens to aqueous [Al(H2O)6]3+ when NH3 is added?

Answer 5

Colourless solution forms white precipitate

Question 6

What happens to aqueous [Al(H2O)6]3+ when excess NaOH is added?

Answer 6

Colourless solution forms white precipitate then the white precipitate dissolves to form a colourless solution

Question 7

What happens to aqueous [Fe(H2O)6]3+ when NH3 is added?

Answer 7

Brown solution forms brown precipitate

Question 8

What happens to aqueous [Fe(H2O)6]3+ when Na2CO3 is added?

Answer 8

Brown solution forms brown precipitate and CO2 is released

Question 9

What happens to aqueous [Al(H2O)6]3+ when Na2CO3 is added?

Answer 9

Colourless solution forms white precipitate and CO2 is released

Question 10

What happens to aqueous [Fe(H2O)6]3+ when excess NH3 is added?

Answer 10

Brown solution forms brown precipitate
No further change

Question 11

What happens to aqueous [Fe(H2O)6]3+ when excess NaOH is added?

Answer 11

Brown solution forms brown precipitate
No further change

Question 12

What happens to aqueous [Cu(H2O)6]2+ when NaOH is added?

Answer 12

Blue solution forms blue precipitate

Question 13

What happens to aqueous [Cu(H2O)6]2+ when NH3 is added?

Answer 13

Blue solution forms blue precipitate

Question 14

What happens to aqueous [Cu(H2O)6]2+ when excess NaOH is added?

Answer 14

Blue solution has already formed a blue precipitate
No further change

Question 15

What happens to aqueous [Fe(H2O)6]2+ when excess NaOH is added?

Answer 15

Green solution has already formed a green precipitate
No further change

Question 16

What happens to aqueous [Fe(H2O)6]2+ when excess NH3 is added?

Answer 16

Green solution has already formed a green precipitate
No further change

Question 17

What coulour is aqueous [Cu(H2O)6]2+

Answer 17

Blue solution

Question 18

What coulour is aqueous [Al(H2O)6]3+

Answer 18

colourless solution

Question 19

What coulour is aqueous [Fe(H2O)6]3+

Answer 19

Purple solution but looks brown due to some dissociation into
[Fe(H2O)5(OH)]2+

Question 20

What happens to aqueous [Fe(H2O)6]2+ when NH3 is added?

Answer 20

Green solution forms green precipitate
(goes brown on standing in air)

Question 21

What happens to aqueous [Fe(H2O)6]2+ when Na2CO3 is added?

Answer 21

Green solution forms a green precipitate of FeCO3

Question 22

What happens to aqueous [Cu(H2O)6]2+ when HCl is added?

Answer 22

Blue solution forms a yellow-green solution of [CuCl4]2-

Question 23

What happens to aqueous [Cu(H2O)6]2+ when Na2CO3 is added?

Answer 23

Blue solution forms a blue-green precipitate of CuCO3

Question 24

What happens to aqueous [Cu(H2O)6]2+ when excess NH3 is added?

Answer 24

Blue solution forms blue precipitate which then forms a deep blue solution

Question 25

What happens to aqueous [Al(H2O)6]3+ when excess NH3 is added?

Answer 25

Colourless solution forms white precipitate
No further change