Tests

Question 1

What is the test for chlorine gas

Answer 1

Turns damp blue litmus paper red then bleaches it

Question 2

What is the test for NH3

Answer 2

Turns damp red litmus blue

Question 3

Flame test colour for Lithium

Answer 3

Crimson

Question 4

Flame test colour for Sodium

Answer 4

Yellow

Question 5

Flame test colour for Potassium

Answer 5

Lilac

Question 6

Flame test colour for Calcium

Answer 6

Orange-red

Question 7

Flame test colour for Copper

Answer 7

Green

Question 8

What do dilute NaOH and NH3 test for

Answer 8

Positive ions (Al, Ca, Cu, Fe, Zn, Mg)

Question 9

Result of Al 3+ reacting with NaOH

Answer 9

White precipitate, soluble in excess

Question 10

Result of Al 3+ reacting with NH3

Answer 10

White precipitate, insoluble in excess

Question 11

Result of Ca 2+ reacting with NaOH

Answer 11

White precipitate, insoluble in excess

Question 12

Result of Ca 2+ reacting with NH3

Answer 12

No/very slight precipitate, no effect with excess

Question 13

Result of Cu 2+ reacting with NaOH

Answer 13

Light blue precipitate, insoluble in excess

Question 14

Result of Cu 2+ reacting with NH3

Answer 14

Light blue precipitate, soluble in excess (dark blue solution)

Question 15

Result of Fe 2+ reacting with NaOH

Answer 15

Green precipitate, insoluble in excess

Question 16

Result of Fe 2+ reacting with NH3

Answer 16

Green precipitate, insoluble in excess

Question 17

Result of Fe 3+ reacting with NaOH

Answer 17

Brown precipitate, insoluble in excess

Question 18

Result of Fe 3+ reacting with NH3

Answer 18

Brown precipitate, insoluble in excess

Question 19

Result of Zn 2+ reacting with NaOH

Answer 19

White precipitate, soluble in excess (colourless solution)

Question 20

Result of Zn 2+ reacting with NH3

Answer 20

White precipitate, soluble in excess (colourless solution)

Question 21

Result of Mg 2+ reacting with NaOH

Answer 21

White precipitate, insoluble in excess

Question 22

Result of Mg 2+ reacting with NH3

Answer 22

White precipitate, insoluble in excess

Question 23

Test for NH 4+

Answer 23

Heat ammonium salt with dilute NaOH, releases NH3

Question 24

Test for carbonates

Answer 24

Add dilute acid, and test for carbon dioxide

Question 25

Test for sulphates

Answer 25

Add dilute HCl to sample, add BaCl2 or Ba(NO3)2

Question 26

Positive result for sulphates

Answer 26

White precipitate of Barium Sulphate

Question 27

Test for nitrates

Answer 27

Add dilute NaOH and aluminium foil to sample, warm gently, test for NH3

Question 28

Test for halides

Answer 28

Add dilute HNO3 to sample, add silver nitrate, a silver halide precipitate forms

Question 29

Colour of silver chloride

Answer 29

White

Question 30

Colour of silver bromide

Answer 30

Cream

Question 31

Colour of silver iodide

Answer 31

Yellow