Chaper 6 - Chemical Tests

Question 1

What’s the test for water ?

Answer 1

Add it to anhydrous copper sulfate. Turns from a white powder to blue.

Question 2

Colour of lithium in a flame test.

Answer 2

Crimson

Question 3

Colour of sodium in a flame test

Answer 3

Yellow/orange

Question 4

Colour of potassium in flame test

Answer 4

Lilac

Question 5

Colour of calcium in flame test

Answer 5

Brick-red

Question 6

Colour of copper in flame test

Answer 6

Blue-green

Question 7

Results of ammonia/sodium hydroxide test of copper.

Answer 7

Blue pot of copper hydroxide forms. In excess - blue pot remains.

Question 8

Results of ammonia/sodium hydroxide test of iron(ii)

Answer 8

Green ppt of iron hydroxide. Excess green ppt remains.

Question 9

Results of ammonia/sodium hydroxide test of Iron(iii)

Answer 9

Brown ppt forms. In excess brown ppt remains.

Question 10

Results of ammonia/sodium hydroxide test of magnesium.

Answer 10

White ppt of mg hydroxide forms. In excess white ppt stays the same.

Question 11

Results of ammonia/sodium hydroxide test of aluminium

Answer 11

White ppt forms . Excess NaOH white ppt dissolves and colourless solution is formed. Excess NH3 white ppt remains.

Question 12

Results of ammonia/sodium hydroxide test of zinc

Answer 12

White ppt forms. Excess NaOH ppt dissolves forming colourless solution. NH3 colourless solution formed.

Question 13

Halide test : results for chloride ions

Answer 13

White ppt forms of silver chloride

Question 14

Halide test : results for bromide ions

Answer 14

Cream ppt forms of silver bromide

Question 15

Halide test : results for iodide ions

Answer 15

Yellow pot of silver iodide forms

Question 16

Test for sulfate ions

Answer 16

Add barium sulfate. White ppt forms.

Question 17

How do you carry out the test for carbonate ions.

Answer 17

• add HCL
• test gas produced with limewater
• limewater should go from colourless to milky