Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A Level Chemistry > 2.6 Reactions of ions in aqueous solution > Flashcards

2.6 Reactions of ions in aqueous solution Flashcards

1
Q

What happens when Fe2+ reacts with dilute sulphuric acid
- state observation
- state complex ion formed

A

observation : pale green solution
formula : {Fe(H2O)6}^2+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

state formula of precipitate and observation when {Fe(H2O)6}^2+ is added to sodium hydroxide
- write equation

A

observation : green solution turns into a pale green precipitate
formula : Fe(OH)2(H2O)4
equation: Fe(H2O)6]2+ + 2OH- → Fe(H2O)4(OH)2 + 2H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

state formula of precipitate and observation when Fe(OH)2(H2O)4 is allowed to stand in air

A

observation : brown precipitate
formula : Fe(OH)3(H2O)3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what happens when Cu^2+ dissolves in nitric acid
- state observation
- state formula
- write equation

A

observation : blue solution formed
formula : [Cu(H2O)6]2+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what happens when excess concentrated hydrochloric acid is added to [Cu(H2O)6]2+
- state formula
- state observation
- state equation

A

observation : yellow - green solution
formula : CuCl4^2-
equation : [Cu(H2O)6]2+ + 4Cl^- -> CuCl4^2- + 6H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what happens when aqueous ammonia is added to [Cu(H2O)6]2+
- state formula
- state observation
- write an equation for its formation
b) do the same for when an excess ammonia is added to the new ion

A

observation : blue precipitate
formula : Cu(OH)2(H2O)4
equation : Cu(H2O)6 ^2+ + 2NH3 -> Cu(OH)2(H2O)4 + 2NH4^+
b) formula : [Cu(NH3)4(H2O)2]^2+
observation : dark/deep blue solution
equation : Cu(H2O)4(OH)2 + 4NH3 -> Cu(NH3)4(H2O)^2+ 2H2O + 2OH^-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what happens when Na2CO3 is added to [Cu(H2O)6]2+ (aq)
- state formula
- state observation
- write an equation for its formation

A

formula : CuCO3
green precipitate
[Cu(H2O)6]^2+ + CO3^2- -> CuCO3 + 6H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Copper metal can be extracted from dilute aqueous solution containing copper (ii) ions using scrap ion
- state initial and final colour
- write an equation for its formation

A

initial : blue
final : green
equation : Cu^2+ (aq) + Fe(s) -> Cu (s) + Fe^2+ (aq)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what happens when Na2CO3 is added to [Fe(H2O)6]3+ (aq)
- state initial colour and final observation
- write an equation for its formation

A

brown solution gives a brown precipitate
effervescence
2[Fe(H2O)6]3+ + 3CO3^2– → 2Fe(H2O)3(OH)3 + 3CO2 + 3H2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what happens when Na2CO3 is added to [Al(H2O)6]3+ (aq)
- state observation
- write an equation for its formation

A

white precipitate
effervescence
2[Al(H2O)6]^3+ + 3CO3^2- -> 2[Al(H2O)3(OH)3] + 3CO2 + 3H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what happens when Na2CO3 is added to [Fe(H2O)6]2+ (aq)
- state initial colour and final observation
- write an equation for its formation

A

green solution gives a green precipitate
[Fe(H2O)6]2+ + CO32− → FeCO3 + 6H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what happens when excess concentrated HCl is added to [Co(H2O)6]^2+
- state initial colour and final observation
- write an equation for its formation

A

pink solution turns into a brown solution
[Co(H2O)6]2+ + 4Cl− → [CoCl4]^2− + 6H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what happens when dilute aqueous ammonia is added to [Al(H2O)6]3+ (aq)
- state observation
- write an equation for its formation

A

colourless solution gives a white precipitate
[Al(H2O)6]3+ + 3NH3 → Al(H2O)3(OH)3 + 3NH4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what happens when dilute aqueous ammonia is added to [Ag(H2O)2]^+
- state observation
- write an equation for its formation

A

no visible change as colourless solution remains a colourless solution
[Ag(H2O)2]+ + 2NH3 → [Ag(NH3)2]+ + 2H2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what forms with NaOH and Na2CO3 to form a white precipitate

A

Calcium & magnesium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is formed when aluminium reacts with NaOH and Na2CO3

A

NaOH : white precipitate, dissolves in NaOH
Na2CO3 : white precipitate, bubbles of gas

17
Q

An aqueous solution of Y gave a cream precipitate of Compound A when reacted with silver nitrate solution
Compound A gave a colourless solution when reacted with concentrated ammonia solution
Identify A

A

Silver bromide

18
Q

Aqueous solution of Y gave a green precipitate B when reacted with sodium carbonate
- Identify B & write the simplest ionic equation that occurs when green precipitate B and sulfuric acid react
green precipitate of B was filtered and dried and then reacted with sulfuric acid to give a pale green solution containing compound C and a colourless gas D
Identify C and D

A

B: FeCO3 Iron (ii) carbonate
equation : 2H+ + CO3^2- -> H2O + CO2
C: Iron (ii) sulphate FeSO4
D: CO2

19
Q

Solution A contains the compound [Cu(H2O)6]Cl2
State the type of bonding between the oxygen and hydrogen in this compound.
b) state why chloride ions in this compound are not considered to be ligands

A

Covalent bonding
b) they are not donating a lone pair to the metal ion
and it doesn’t form a coordinate bond to the metal ion

20
Q

what is a complex ion

A

A complex ion is a positive metal ion surrounded by ligands. The ligands bond to the central metal ion by co-ordinate bonds

21
Q

define a coordinate bond

A

a coordinate bond is a shared pair of electrons which have both come from the same atom

22
Q

define a ligand

A

A Ligand is an ion or molecule with a lone pair of electrons which can form a coordinate bond with a metal ion

23
Q

what is the coordination number

A

the number of coordinate bonds a transition metal ion forms

24
Q

what happens when an excess of ammonia is added to [Cu(H2O)6]Cl2
- state observation
- write an equation for its formation

A

Cu(H2O)4(OH)2 + 4NH3 -> Cu(NH3)4(H2O)^2+ 2H2O + 2OH^-
deep blue solution formed

25
Q

When anhydrous aluminium chloride reacts with water, solution Y is formed that contains a complex aluminium ion, Z, and chloride ions.
Give an equation for this reaction.
b) Give an equation to show how the complex ion Z can act as a Brønsted–Lowry acid with water.

A

AlCl3 + 6H2O -> [Al(H2O)6]^3+ + 3Cl
b) [Al(H2O)6]^3+ + H2O -> [Al(H2O)5(OH)]2+ + H2O^-

26
Q

state the colour of a) [Cu(H2O)6]2+
b) [Fe(H2O)6]2+
c) [Fe(H2O)6]3+
d) [Al(H2O)6]3

A

a) Blue solution Pale
b) green solution
c) Yellow brown solution
d) Colourless solution

27
Q

write equation of Fe(III) complex acting as an acid

A

Fe(H2O)6]3+ → [Fe(H2O)5(OH)]2+ + H+

28
Q

Aqueous potassium hydroxide is added, until in excess, to [Al(H2O)6]^3+
Describe two observations you would make.
For each observation give an equation for the reaction that occurs.

A

Observation 1 : colourless solution to white precipitate
equation 1 : Al(H2O)6]3+ + 3OH- → Al(H2O)3(OH)3 + 3H2O
observation 2: White precipitate dissolves to form a colourless solution
equation 2 : Al(H2O)3(OH)3 + OH- → [Al(H2O)2(OH)4]- + H2O

29
Q

state what is observed and give equation for when [Fe(H2O)6]^2+ reacts with Na2CO3

A

Observation : green solution to green precipitate
equation : Fe(H2O)6]2+ + CO32- → FeCO3(s) + 6H2O

30
Q

state what is observed and give equation for when [Fe(H2O)6]^2+ reacts with NH3

A

Observation : green solution turns into green precipitate
equation : [Fe(H2O)6]2+ + 2NH3 → Fe(H2O)4(OH)2 + 2NH4+

31
Q

reagent to turn [Fe(H2O)6]^3+ -> [Fe(H2O)6]^2+

A

Excess H2SO4

32
Q

why, with use of an equation., a solution containing [Al(H2O)6]^3+ has a pH less than 7

A

Al(H2O)6]3+ ⇌ [Al(H2O)5(OH)]2+ + H+
Al3+ has a small size and high charge
Weakens the OH bond (in water) releasing H+ ions

33
Q

Explain why an aqueous solution containing [Fe(H2O)6]3+ ions has a lower pH than an aqueous solution containing [Fe(H2O)6]2+ ions.

A
  • [Fe(H2O)6]^3+ has a higher charge and is smaller
  • Fe^3+ is more polarising as it polarises water molecules more
  • more OH bonds in the water ligands break and hence more OH^+ ions are released
34
Q

When anhydrous aluminium sulphate, Al2(SO4)3, is added to water a solution forms that contains the complex aluminium ion, [Al(H2O)6]3+Give the equation for the reaction

A

Al2(SO4)3 + 12 H2O → 2 [Al(H2O)6]3+ + 3 SO42-

35
Q

Explain why the solution containing [Al(H2O)6]3+ is acidic

A

Al3+ has a high charge and small size
Al3+ weakens the O-H bond (in water ligands and donates H+ to water or forms H3O+ ions with water

A Level Chemistry (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions