Tests for Ions

Flame Test Lithium (Li+):
Crimson (Red)
1 of 26
Flame Test Sodium (Na+):
Yellow
2 of 26
Flame Test Potassium (K+):
Lilac
3 of 26
Flame Test Calcium (Ca²+):
Red
4 of 26
Flame Test Barium (Ba²+):
Green
5 of 26
Metal Hydroxides:
Hydroxides of most metals that have ions with 2+ or 3+ charges are insoluble in water. When sodium hydroxide is added to these solutions a precipitate of the metal hydroxide forms.
6 of 26
Copper (II) Hydroxide:
Blue
7 of 26
Iron (II) Hydroxide:
Green
8 of 26
Iron (III) Hydroxide:
Brown
9 of 26
Aluminium Hydroxide:
White
10 of 26
Calcium Hydroxide:
White
11 of 26
Magnesium Hydroxide:
White
12 of 26
To differentiate between the metal hydroxides we add excess sodium hydroxide. What are the results from this?
The precipitate of aluminium hydroxide dissolves and we can use the flame test for the other metal hydroxides.
13 of 26
What is the reaction for calcium ions and the sodium hydroxide solution?
Ca²(aq) + 2OH-(aq) → Ca(OH)2(s) (sodium not included)
14 of 26
To test for carbonate ions what substance is added?
Dilute hydrochloric acid.
15 of 26
If the substance contains carbonate ions what will happen?
The substance will fizz and the gas produced turns limewater milky.
16 of 26
What is the reaction if there are calcium carbonate ions?
2HCl(aq) + CaC03(s) → CaCl2(aq) + H2O(l) + CO2(g)
17 of 26
To test for halide ions what solutions do we add?
Dilute nitric acid and then a silver nitrate solution.
18 of 26
What colour precipitate does chloride give?
white
19 of 26
What colour precipitate does bromide give?
cream
20 of 26
What colour precipitate does iodide give?
yellow
21 of 26
Why must you add nitric acid and not hydrochloric acid or sulfuric acid when testing with silver nitrate solution for halides?
Hydrochloric acid gives chloride ions (Cl-) and sulfuric acid contains sulfate ions (SO4-2) which both give precipitates with silver nitrate solution.
22 of 26
What is the reaction if there are sodium chloride ions?
AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)
23 of 26
What solutions do we use to test for sulfate ions?
Dilute hydrochloric acid and then barium chloride.
24 of 26
If sulfate ions are present what will form?
A white precipitate.
25 of 26
What is the reaction if Magnesium Sulfate ions are present?
BaCl2(aq) + MgSO4(aq) → BaSO4(s) + MgCl2(aq)
26 of 26

Other cards in this set

Card 2

Front

Flame Test Sodium (Na+):

Back

Yellow

Card 3

Front

Flame Test Potassium (K+):

Back

Preview of the front of card 3

Card 4

Front

Flame Test Calcium (Ca²+):

Back

Preview of the front of card 4

Card 5

Front

Flame Test Barium (Ba²+):

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 Analysing substances resources »