Transition Metal Reactions

?
Describe the procedure for testing for a transition metal ion using sodium hydroxide.
Add NaOH dropwise to a testube containing the unknown solution. Record the colour of any precipitate formed.
1 of 17
why does the green precpipitate of Iron(II) oxide go brown on the surface, if left standing in air?
Because Fe2+ is easily oxidised to Fe3+
2 of 17
What colour is the Mn(OH)2 aka Manganese (II) hydroxide precipitate?
pink/buff
3 of 17
What happens to [Cr(OH)3(H20)3] when excess hydroxide is added?
the precipitate redissolves
4 of 17
How would you describe a precipitate of [Cu(OH)2(H2O)4]
A blue gelatinous precipitate
5 of 17
Why do hydroxide precipitates form initially when tranisition metal ions are reacted with ammonia?
Because ammonia acts as a base accepting (i.e. removing) hydrogen ions from the water molecules
6 of 17
What colour is the precipitate [Fe(OH)2(H2O)3] aka iron (II) hyroxide?
Dark green
7 of 17
What colour is the precipitate [Fe(OH)3(H20)3] aka iron (III) hydroxide?
rusty brown/orange
8 of 17
What colour is the precipitate [Cr(OH)3(H2O)3] aka chromium (III) hydroxide?
grey-green
9 of 17
what is the bond angle in a copperhexaaqua complex ion and why is this?
90 degrees- because it is an octahedral complex
10 of 17
What happens when excess ammonia is added to copper (II) hydroxide?
the blue precipitate will completely dissolve to leave a deep blue solution
11 of 17
what can be used as a source of chloride ions in a ligand susbtitution reaction?
Concentrated hyrochloric acid
12 of 17
During the reaction between Cu2+ and Cl-, why does the solution in the test tube appear green?
Because the hexaaquacopper ion is blue whereas the [CuCl4]2- ion is yellow. The reaction is reversible and therefore an equilibrium exists between the two colours
13 of 17
Why is [CuCl4]2- a tetrahedral complex?
because chloride ions are bigger than water and ammonia molecules so only four can physically fit around the central copper ion
14 of 17
What colour is a solution of [Co(H2O)6] aka hexaaquacobalt?
pink
15 of 17
what happens to a solution of hexaaquacobalt when concentrated hydrochloric acid is added?
the product [CoCl4]2- is formed which causes the solution to turn blue
16 of 17
what is the bond angle in a tetrahedral complex?
109.5 degrees
17 of 17

Other cards in this set

Card 2

Front

why does the green precpipitate of Iron(II) oxide go brown on the surface, if left standing in air?

Back

Because Fe2+ is easily oxidised to Fe3+

Card 3

Front

What colour is the Mn(OH)2 aka Manganese (II) hydroxide precipitate?

Back

Preview of the front of card 3

Card 4

Front

What happens to [Cr(OH)3(H20)3] when excess hydroxide is added?

Back

Preview of the front of card 4

Card 5

Front

How would you describe a precipitate of [Cu(OH)2(H2O)4]

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Transition metals resources »