Reactions of aqueous ions

Question 1

State what is meant by a lewis base

Answer 1

electron pair donor

Question 2

State what is meant by a lewis acid

Answer 2

an electron pair acceptor

Question 3

Are metal aqau ions acidic or basic in solutions

Answer 3

Acidic

Question 4

Why can 3+ metal ions dissociate more readily than 2+

Answer 4

• 3+ are more acidic
• because 3+ metal ions have a higher charge density than 2+ ions
• so 3+ are more ploarising than 2+, they attract the OH bond in the water more strongly, which weakens the bond
• which makes it more likley to be broken

Question 5

Metal hydroxides can be amphoteric

State what is meant by this

Answer 5

act as an acid or base

Question 6

How do you form a Hexaaqua metal compleex

Answer 6

dissolve metal salt in water

Question 7

What happens to metal complexes when they are hydroxylised

Answer 7

• OH from the water acts as a nucelophile and donates a lone pair to the hydrogen
• this goes on to make water
• leaving the metal with water ligands and hydroxide ligands

Question 8

If something has a large KA what can of acid is it

Answer 8

Strong

Question 9

What happens when you react [Cu(h20)6]2+ with NaOH

Answer 9

[Cu(H2O)6]2+ (aq) + 2OH- (aq) ->Cu(H20)4(OH)2 (s) + 2H2O (l)

Blue solution to blue ppt

Question 10

What happens when you react [Fe(h20)6]2+ with NaOH

Answer 10

[Fe(H2O)6]2+ (aq) + 2OH- (aq) ->FE(H20)4(OH)2 (s) + 2H2O (l)

Green solution to green ppt that goes brown when in air

Question 11

What happens when you react [Fe(h20)6]3+ with NaOH

Answer 11

[Fe(H2O)6]3+ (aq) + 3OH- (aq) ->Fe(H20)3(OH)3 (s) + 3H2O (l)

Purple solution to brown ppt

Question 12

What happens when you react [Al(h20)6]3+ with NaOH

Answer 12

[Al(H2O)6]3+ (aq) + 2OH- (aq) ->Al(H20)3(OH)3 (s) + 3H2O (l)

colourless solution to white ppt
also there 3 hydroxide ligands now

Question 13

What happens when you react [Cu(h20)6]2+ with excess NaOH

Answer 13

No further change remains blue ppt

Question 14

What happens when you react [Fe(h20)6]2+ with excess NaOH

Answer 14

No further change, remains a green/brown ppt

Question 15

What happens when you react [Fe(h20)6]3+ with excess NaOH

Answer 15

No further change remains brown ppt

Question 16

What happens when you react [Al(h20)6]3+ with excess NaOH

Answer 16

makes a colourless solution

[Al(h20)2(OH)4]-

Question 17

What happens when you react [Cu(h20)6]2+ with NH3

Answer 17

[Cu(H2O)6]2+ (aq) + 2OH- (aq) ->Cu(H20)4(oh-)2 (s) + 2H2O (l)

Blue solution to blue ppt

Question 18

What happens when you react [Fe(h20)6]2+ with NH3

Answer 18

[Fe(H2O)6]2+ (aq) + 2OH- (aq) ->Fe(H20)4(OH)2 (s) + 2H2O (l)

Green solution to green/brown ppt

Question 19

What happens when you react [Fe(h20)6]3+ with NH3

Answer 19

[Fe(H2O)6]3+ (aq) + 2OH- (aq) ->Fe(H20)3(OH)3 (s) + 3H2O (l)

Purple solution to brown ppt

Question 20

What happens when you react [Al(h20)6]3+ with NH3

Answer 20

[Al(H2O)6]3+ (aq) + 2OH- (aq) ->Al(H20)3(OH)3 (s) + 3H2O (l)

Colourless sol to white ppt

Question 21

What happens when you react [Al(h20)6]3+ with excess NH3

Answer 21

No further change, stays at white ppt

Question 22

What happens when you react [Fe(h20)6]3+ with excess NH3

Answer 22

No further change, stays brown ppt

Question 23

What happens when you react [Fe(h20)6]2+ with excess NH3

Answer 23

No further change, stays green/brown ppt

Question 24

What happens when reacting [Cu(H2o)6]2+ with excess ammonia

Answer 24

Forms a deep blue solution, because of ligand substitution

[Cu(H2o)2(NH3)4]2+ aq

Question 25

What happens when you react

[Cu(H2O)6]2+ + CO3 2-

Answer 25

you form

CuCO3 (s) + 6h20
blue green ppt

Question 26

What happens when you react

[FeH2O)6]2+ + CO3 2-

Answer 26

you form

FeCO3 (s) + 6h20
green ppt

Question 27

What happens when you react

2[FeH2O)6]3+ + 3CO3 2-

Answer 27

you form

2[Fe(H2o)3(OH)3] (s) + 3h20 +3Co2
brown ppt and Co2

Question 28

What happens when you react

2[FeH2O)6]3+ + 3CO3 2-

Answer 28

you form

2[Fe(H2o)3(OH)3] (s) + 3h20 +3Co2
brown ppt and Co2