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RESULTS: Exercise 1: Qualitative Anion Tests Data Table 1. Anion Confirmation Te

ID: 1018804 • Letter: R

Question

RESULTS:

  Exercise 1: Qualitative Anion Tests

Data Table 1. Anion Confirmation Tests.

Chemical

Anion

Addition of AgNO3

Addition of HCl

NaBr

Bromide

It became white and cloudy

Still was white and cloudy

Na2CO3

Carbonate

Clear inside white and cloudy around the outside

Still white and cloudy but bubbles start to form.

NaCl

Chloride

Turn white cloudy on bottom clear on top

Still white cloudy on bottom clear on top

NaI

Iodide

In the middle very dark and cloudy fades out lighter white around the middle

Became a little seperate

Na2SO4

Sulfate

clear

Became white and cloudy

Na2S

Sulfide

Turn a brown color in the middle but separated from the clear

The brown becomes more separate from the clear

Unknown #103

carbonate

White and cloudy

White and cloudy bubbles form

Unknown #104

sulfide

Turn brown color in the middle

Some of the brown disappeared and became seperate

Use your results and observations in Data Table 1 to create a flow chart for identification of unknown anions, using the AgNO3 and HCl confirmation tests. Insert the flow chart below.

Data Table 2. Cation Flame Tests.

Chemical

Cation

Flame Observations

KI

Potassium

light pink

CaCl2

Calcium

Red

LiOH

Lithium

Dark pink

NaCl

Sodium

Orange

Cu(NO3)2

Copper

Light blue

Unknown #105

copper

Light blue

Unknown #106

potassium

Light pink

Unknown #107

calcium

red

Data Table 3. Complete Chemical Identification.

Chemical

Cation

Anion Test Observations

Anion

Complete Chemical Name and Formula

Unknown #105

copper

No change

No3^2-

Copper nitrate

Unknown #106

potassium

Dark in the middle and fades lighter

l-

Potassium iodide

Unknown #107

calcium

Turn white and clouy

Cl-

Calcium chloride

Use your results and observations in Data Tables 1, 2, and 3, to create a flow chart for the identification of an unknown (both an unknown anion and cation), using the AgNO3 and HCl confirmation tests and the cation flame tests.

Chemical

Anion

Addition of AgNO3

Addition of HCl

NaBr

Bromide

It became white and cloudy

Still was white and cloudy

Na2CO3

Carbonate

Clear inside white and cloudy around the outside

Still white and cloudy but bubbles start to form.

NaCl

Chloride

Turn white cloudy on bottom clear on top

Still white cloudy on bottom clear on top

NaI

Iodide

In the middle very dark and cloudy fades out lighter white around the middle

Became a little seperate

Na2SO4

Sulfate

clear

Became white and cloudy

Na2S

Sulfide

Turn a brown color in the middle but separated from the clear

The brown becomes more separate from the clear

Unknown #103

carbonate

White and cloudy

White and cloudy bubbles form

Unknown #104

sulfide

Turn brown color in the middle

Some of the brown disappeared and became seperate

Explanation / Answer

As given in the tables and data

Unkown 103

(i) Unkown anion : It is becomes white and cloudy on addition of AgNO3 and bubbles are formed on addition of HCl so it must be carbonate.

Unkown 104

(i) unkown anion: Turn brown color in the middle on additon of AgNO3 : it must be bromide ion

Cation flame tes

(i) Unkown 105: Light blue colour so must be copper ion

Unknown 106 :Light pink so must be potassium cation

Unkown 107 : Red colour so must be Calcium ion

(ii) for anion

Unkown 105 : No change on addition of AgNO3 : so the anion must be nitrate ion

So the salt is Cu(NO3)2

Unkown 106: Dark in the middle and fades lighter: so must be iodide ion

The salt will be

KI

Unknown 107 : Turn white and cloudy: chloride ion

so the salt is CaCl2

The flow chart will be

Step 1: Addition of AgNO3 to three unkown

a) White ppt forms with 107 so : Chloride ion is present

b) Dark in the middle and fades lighter: Iodide ion is present

c) No change:Nitrate ion is present

Flame test

(i) Red colour For 107 : Calcium ion is present

(ii) light pink for 106 : K+ is present

(iii) Light blue for 105: Copper ion is present