C4

Question 1

Hydrogen gas test

Answer 1

Lighted splint ignites with pop

Question 2

Oxygen gas test

Answer 2

Glowing splint relights

Question 3

Chlorine gas test

Answer 3

Damp blue litmus paper turns red then white

Question 4

Carbon dioxide gas test

Answer 4

Turns limewater cloudy

Question 5

Reactivity series

Answer 5

Potassium,sodium,calcium,magnesium,aluminium,zinc,iron,tin,lead,(hydrogen),copper,silver,gold,platinum

Question 6

Flame test

Answer 6

Nichrome wire cleaned in dilute HCl before every test, held in flame until no flame colour is produced and then dipped in solution and put in flame, colour observed

Question 7

Lithium flame test

Answer 7

Red

Question 8

Sodium flame test

Answer 8

Yellow

Question 9

Potassium flame test

Answer 9

Lilac

Question 10

Calcium flame test

Answer 10

Orange-red

Question 11

Copper flame test

Answer 11

Green-blue

Question 12

Hydroxide precipitate test

Answer 12

Sodium hydroxide added to form metal hydrogen precipitate

Eg- NaOH + CuX -> NaX + CuOH(precipitate)

Question 13

Iron(II) precipitate test

Answer 13

Green

Question 14

Iron(III) precipitate test

Answer 14

Orange-brown

Question 15

Copper precipitate test

Answer 15

Blue

Question 16

Calcium precipitate test

Answer 16

White

Question 17

Zinc precipitate test

Answer 17

White (dissolves in excess NaOH)

Question 18

Halide ion test

Answer 18

Dilute nitric acid and silver nitrate added to produce silver halide

Question 19

Chloride precipitate

Answer 19

White

Question 20

Bromine precipitate

Answer 20

Cream

Question 21

Iodide precipitate

Answer 21

Yellow

Question 22

Why isn’t HCl used in the halide ion test?

Answer 22

Hcl has chloride ions, which may lead to a false positive in the test

Question 23

Sulphate ion test

Answer 23

Dilute Hydrochloric acid and barium chloride to for barium sulphate (white precipitate)

Question 24

Carbonate ion test

Answer 24

Add dilute nitric acid, collect gas produced (seen by bubbles) and do carbon dioxide limewater test

Question 25

Alkali metals properties

Answer 25

Shiny, mostly solid at 20c, float on water,reactive, group 1

Question 26

Alkali metal properties (going down group)

Answer 26

- increasing reactivity - decreasing melting point - decreasing hardness - increasing density

Question 27

Halogens properties

Answer 27

Non metals, reactive, forms salt when reacted with metals

Question 28

Halogen properties (going down the group)

Answer 28

- increasing melting point - decreasing reactivity - increasing boiling point - increasing density

Question 29

Why does the reactivity decrease as you go down group 7 but increase as you go up group 1?

Answer 29

- group 1 are metals, metals lose electrons on their outer shells - Having a shell further away from the nucleus means that the attraction of opposite charges between the nucleus and the outer electrons is weaker.This means that it is easier for the atom to lose its outer electrons. - this makes group 1 elements more reactive as more electron shells are present - group 7 are non metals , non metals lose electrons on their outer shells - Having a shell further away from the nucleus means that the attraction of opposite charges between the nucleus and the outer electrons is weaker.This means that it is harder for the atom to gain outer electrons. - this makes group 7 elements less reactive as more electron shells are present

Question 30

Fluorine

Answer 30

Pale yellow gas

Question 31

Chlorine

Answer 31

Yellow/green gas

Question 32

Bromine colour

Answer 32

Reddish-brown liquid

Question 33

Iodine

Answer 33

Shiny grey solid (sublimes to purple vapour)

Question 34

Astatine

Answer 34

Black solid

Question 35

Nobel gases properties

Answer 35

gases at room temperature, inert, group 0

Question 36

Nobel gases properties (going down group)

Answer 36

- increasing melting point - increasing boiling point - increasing density (because density of gases at room temp remain the same but the molar mass increases)

Question 37

Transition metals properties

Answer 37

Form coloured ions,multiple oxidation states, catalysts, malleable, shiny, higher melting points and less reactive than group 1 elements, mostly form 2+ ions.

Question 38

Benefits of instrumental methods of analysis

Answer 38

- More sensitive to smaller substances - Much more accurate - Much more quicker