3.2.6 Reactions of ions in aqueous solution

Question 1

Iron(II) aqueous ion + colour

Answer 1

[Fe(H2O)6]2+ (aq)
Green solution

Question 2

Iron(II) aqueous ion + NaOH + colour

Answer 2

Fe(H2O)4(OH)2 (s)
Green ppt goes brown on standing in air

Question 3

Iron(II) aqueous ion + NH3 + colour

Answer 3

Fe(H2O)4(OH)2 (s) + 2NH4+
Green ppt goes brown on standing in air

Question 4

Iron(II) aqueous ion + CO3 2- + colour

Answer 4

FeCO3 (s) + 6H2O
Green ppt

Question 5

Copper(II) aqueous ion + colour

Answer 5

[Cu(H2O)6]2+ (aq)
Blue solution

Question 6

Copper(II) aqueous ion + NaOH + colour

Answer 6

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

Question 7

Copper(II) aqueous ion + NH3 + colour

Answer 7

Cu(H2O)4(OH)2 (s) +
2NH4+
Blue ppt

Question 8

Copper(II) aqueous ion + CO3 2- + colour

Answer 8

CuCO3 (s) + 6H2O
Blue-green ppt

Question 9

Copper(II) aqueous ion + excess NH3 + colour

Answer 9

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

Question 10

Iron(III) aqueous ion + colour

Answer 10

[Fe(H2O)6]3+ (aq)
Purple solution

Question 11

Iron(III) aqueous ion + NaOH + colour

Answer 11

Fe(H2O)3(OH) (s)
Brown/orange-brown ppt

Question 12

Iron(III) aqueous ion + NH3 + colour

Answer 12

Fe(H2O)3(OH) (s) + 3NH4+
Brown/orange-brown ppt

Question 13

Iron(III) aqueous ion + CO3 2- + colour

Answer 13

Fe(H2O)3(OH) (s)
Brown/orange-brown ppt
CO2 gas evolved

Question 14

Aluminium aqueous ion + colour

Answer 14

[Al(H2O)6]3+ (aq)
Colourless solution

Question 15

Aluminium aqueous ion + NaOH + colour

Answer 15

Al(H2O)3(OH)3 (s)
White ppt

Question 16

Aluminium aqueous ion + EXCESS NaOH + colour

Answer 16

[Al(OH)4]- (aq)
Colourless solution

Question 17

Aluminium aqueous ion + NH3 + colour

Answer 17

Al(H2O)3(OH)3 (s) + NH4+
White ppt

Question 18

Aluminium aqueous ion + CO3 2- + colour

Answer 18

Al(H2O)3(OH)3 (s)
White ppt
CO2 gas evolved

Question 19

Which acidity is greater [M(H2O)6]3+ or [M(H2O)6]2+

Answer 19

[M(H2O)6]3+