3.2.6 Reactions of ions in aqueous solution

Question 1

what colour is observed when reacting Iron(II) with NaOH and what product is formed

Answer 1

Fe(H2O)4(OH)2 - green ppt goes brown on standing in air

Question 2

what happens when excess NaOH is added to an iron (II) complex

Answer 2

no further change

Question 3

what colour and compound is observed when reacting iron (II) complex with aqueous NH3

Answer 3

Fe(H2O)(OH)2 (s)
- green ppt goes brown on standing in air

Question 4

what do you observe when reacting iron (II) complex with Na2CO3

Answer 4

FeCO3 (s)
- green ppt

Question 5

what is the aqueous ion for copper (II) and what is the colour

Answer 5

[Cu(H2O)6]2+ (aq)
- light blue solution

Question 6

what compound is formed/colour is observed when reacted copper (II) with NaOH

Answer 6

[Cu(H2O)4(OH)2] (s)
blue ppt

Question 7

what happens when you react copper (II) with excess NaOH

Answer 7

no further change

Question 8

what observations/compound is formed when you react [Cu(H2O)6]2+ with NH3

Answer 8

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

Question 9

what observations/compound is formed when you react [Cu(H2O)6]2+ with excess NH3

Answer 9

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

Question 10

what observations/compound is formed when you react [Cu(H2O)6]2+ with Na2CO3 (aq)

Answer 10

CuCO3 (s)
blue-green ppt

Question 11

what does an iron (III) complex look like

Answer 11

[Fe(H2O)6]3+ (aq)
purple solution; may look yellow-brown due to some [Fe(H2O)5(OH)]2+ (aq)

Question 12

what observations/compound is formed when you react [Fe(H2O)6]3+ with NaOH

Answer 12

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

Question 13

what observations/compound is formed when you react [Fe(H2O)6]3+ with excess NaOH

Answer 13

no further change

Question 14

what observations/compound is formed when you react [Fe(H2O)6]3+ with NH3

Answer 14

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

Question 15

what observations/compound is formed when you react [Fe(H2O)6]3+ with excess NH3

Answer 15

no further change

Question 16

what observations/compound is formed when you react [Fe(H2O)6]3+ with Na2CO3

Answer 16

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

Question 17

what does an aluminium (III) complex look like

Answer 17

[Al(H2O)6]3+
colourless solution

Question 18

what observations/compound is formed when you react [Al(H2O)6]3+ with NaOH

Answer 18

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

Question 19

what observations/compound is formed when you react [Al(H2O)6]3+ with excess NaOH

Answer 19

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

Question 20

what observations/compound is formed when you react [Al(H2O)6]3+ with NH3 (aq)

Answer 20

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

Question 21

what observations/compound is formed when you react [Al(H2O)6]3+ with excess NH3

Answer 21

no further change

Question 22

what observations/compound is formed when you react [Al(H2O)6]3+ with Na2CO3 (aq)

Answer 22

Al(H2O)3(OH)3 (s)
white ppt and CO2 gas evolved

Question 23

when the oxidation of vanadium is +5, what is its species in acidic solution and the colour of the solution

Answer 23

[VO2(H2O)4]+
yellow

Question 24

when the oxidation of vanadium is +4, what is its species in acidic solution and the colour of the solution

Answer 24

[VO(H2O)5]2+
blue

Question 25

when the oxidation of vanadium is +3, what is its species in acidic solution and the colour of the solution

Answer 25

[V(H2O)6]3+
green

Question 26

when the oxidation of vanadium is +2, what is its species in acidic solution and the colour of the solution

Answer 26

[V(H2O)6]2+
purple

Question 27

which two equations show how Al(H2O)3(OH)3 is amphoteric

Answer 27

• Al(H2O)3(OH)3 + 3H3O(+) ⇌ [Al(H2O)6]3+ + 3H2O
• Al(H2O)3(OH)3 + OH(-) ⇌ [Al(H2O)2(OH)4]- + H2O