c8: chemical analysis

Question 1

what is steel

Answer 1

mixture/ alloy of iron and carbon

Question 2

what is the brown precipitate formed after mixing metal chloride with sodium hydroxide

Answer 2

iron (III)

Question 3

why are colourings use in food

Answer 3

to improve appearance

Question 4

what is the test for hydrogen

Answer 4

• burning splint held at end of test tube
• will make “squeaky pop” sound

Question 5

what is the test for carbon dioxide

Answer 5

• bubble the gas through limewater (aq calcium hydroxide)
• limewater turns cloudy

Question 6

what is the test for oxygen

Answer 6

• insert a glowing splint into the test tube for gas
• splint will relight

Question 7

what is the test for chlorine

Answer 7

• damp litmus paper into test tube of gas
• bleach litmus paper

Question 8

what is used to identify metal ions

Answer 8

sodium hydroxide

Question 9

what is produced if white precipitate is formed after sodium hydroxide is added to metal ion

Answer 9

calcium, aluminium or magnesium

Question 10

what is produced if blue precipitate is formed after sodium hydroxide is added to metal ion

Answer 10

copper II

Question 11

what is produced if green precipitate is formed after sodium hydroxide is added to metal ion

Answer 11

iron II

Question 12

what is produced if brown precipitate is formed after sodium hydroxide is added to metal ion

Answer 12

iron III

Question 13

what ions produce crimson flame

Answer 13

lithium

Question 14

what ions produce a yellow flame

Answer 14

sodium

Question 15

what ions produce a lilac flame

Answer 15

potassium

Question 16

what ions produce a green flame

Answer 16

copper

Question 17

what ions produce a orange-red flame

Answer 17

calcium

Question 18

what happens when carbonates are reacted with dilute acids

Answer 18

carbon dioxide produced

Question 19

how is a halide test done

Answer 19

adding dilute nitric acid, then silver nitrate

Question 20

what produces white precipitate in halide test

Answer 20

silver chloride

Question 21

what produces cream precipitate in halide test

Answer 21

silver bromide

Question 22

what produces yellow precipitate in halide test

Answer 22

silver iodide

Question 23

what is added to water for sterilisation

Answer 23

chlorine

Question 24

what would form when sodium hydroxide solution is added to aluminium ions

Answer 24

white precipitate, which then dissolves in excess sodium hydroxide

Question 25

what is an advantage of adding fluoride to water

Answer 25

better dental health

Question 26

if a white precipitate is formed after adding hcl to solution and the barium chloride, what sort of ion is the solution

Answer 26

sulfate

Question 27

what solution does the test for sulfate ions use

Answer 27

hcl and barium chloride