Confirmatory test for Iron(II) ion and Iron(III) ion.

REAGENT OBSERVATION CONCLUSION

1. potassium

hexacyanoferrate(II)

solution

Pale blood Iron(III)ion is present

Dark precipitate Iron(III)ion is present

2. potassium

hexacyanoferrate(III)

solution

Dark blue Iron(III)ion is present

Greenish-brown

solution

Iron(III)ion is present

3. potassium

thiocyanate solution

(ammonium thiocyanate

solution)

Pale red colouration Iron(III)ion is present

Blood red colouration Iron(III)ion is present

REAGENT METHOD OBSERVATION CONCLUSION

Using

aqueous

solution of

chloride ions

1. 2cm of potassium chloride solution

(any solution of chloride ion) is

poured into 2cm of solution to be

test

2. The contents obtained are then

diluted are with 5cm of distilled

water and heated until no further

change occur

3. The contents are then allowed to

cool to room temperature using

running water from the tap

• A white precipitate is

formed

• When heated, the

precipitate dissolves

in hot water to form a

colourless solution

• On cooling to room

temperature, the

white precipitate

reappears.

Pb + 2Cl PbCl

Lead(II) chloride is soluble

in hot water but insoluble

in cool water.

The white precipitate

formed is Lead(II)

chloride. Lead(II) ion is

confirmed present in the

solution.

Using

aqueous

solution of

iodide ions

1. 2cm of potassium iodide solution

(any solution of iodide ion) is

poured into 2cm of solution to be

test

2. The contents obtained are then

diluted are with 5cm of distilled

water and heated until no further

change occur

3. The contents are then allowed to

cool to room temperature using

running water from the tap

• A yellow precipitate is

formed

• When heated, the

precipitate dissolves

in hot water to form a

colourless solution

• On cooling to room

temperature, the

yellow precipitate

reappears.

Pb + 2L PbL

Lead(II) iodide is soluble

in hot water but insoluble

in cool water.

The yellow precipitate

formed is Lead(II) iodide.

Lead(II) ion is confirmed

present in the solution.

Confirmatory test for lead(II)ion

2+ +

2+ -

2

2

Confirmatory test for ammonium ion

REAGEN

T

METHOD OBSERVATION CONCLUSIO

N

Heating an

ammoniu

m salt with

an alkali

1. One spatula of solid salt to be tested

(or its aqueous solution) is mixed with

one spatula of solid sodium

hydroxide/ potassium hydroxide/

calcium hydroxide (or it’s aqueous

solution) in a test tube

2. The mixture is heated

3. A piece of moist red litmus paper is

held at the mouth of the test tube

4. The changes that occur are recorded

• A colourless gas that

turns moist red litmus

paper to blue is liberated

The gas

liberated is

ammonia.

Ammonium

ion, NH is

confirmed

present in

solid salt

Reaction

with

Nessler’s

reagent

1. 2 cm of an aqueous solution salt to

be tested is poured into a test tube

2. 2cm of Nessler’s reagent is then

added to the test tube and shaken

well

3. The changes are recorded

• A brown precipitate is

formed

• Nessler’s reagent is an

alkaline solution of

mercury(II) iodide in

potassium iodide and

sodium hydroxide

solution

• Nessler’s reagent

contains complex ions

Ammonium

ion is

confirmed

present in

solid salt

Cation confirmatory

test

Iron(II) ions

Iron(III) ions

Lead(II) ions

Ammonium ions

Potassium

hexacyanoferrate

(III) solution

Potassium

thiocyanate

solution

Potassium

iodide solution

Nessler’s

reagent

Dark blue

precipitate

Blood red

colouration

Yellow

precipitate

Brown

precipitate

C

R

O

S

S

W

O

R

D

Horizontal:

1. Iron (II) ion react with potassium hexacyanoferrate (III) solution will formed _______.

2. Test for lead (II) ions can use two reagents which is using aqueous solution of

iodide ions and _____ ions.

3. Lead (II) chloride is ____ in hot water but insoluble in cool water.

4. When ___, the precipitate (of lead (II) ion) dissolves in hot water to form a colourless

solution.

5. Confirmatory test for ammonium ion can be test by using _________ litmus paper.

6. Ammonium ion is confirmed present in ___ salt.

7. By using aqueous solution of iodide ions, yellow precipitate reappears in _____ room

temperature.

Vertical:

8. Test for iron (III) ion that react with potassium thiocyanate solution will formed ____.

9. Test for ammonium ion by reaction with Nessler’s reagent will formed a ___

precipitate.

10. Test for lead (II) ion using chloride ions on cooling temperature the white precipitate

________.

1

2

3

6

7

8

9

10

11

12

4

5