chapter 6 chemical analysis

Question 1

techniques to separate mixtures

Answer 1

-distillation
-filtration
-crystallisation
-chromatography

Question 2

paper chromatography

Answer 2

analytical method used to separate unknown substances then identify the substances

Question 3

2 phases in paper chromatography

Answer 3

mobile phase: where the molecules can move, this is a liquid or gas
stationary phase: where the molecules cant move, this is either a solid or thick liquid

Question 4

test for chlorine gas

Answer 4

bleaches damp blue litmus paper white

Question 5

text for oxygen gas

Answer 5

relights a glowing splint

Question 6

test for carbon dioxide

Answer 6

limewater turns cloudy

Question 7

test for hydrogen

Answer 7

lit splint in open end of test tube containing hydrogen, makes a pop sound

Question 8

flame tests for metal ions

Answer 8

lithium- crimson flame
sodium- yellow flame
potassium-lilac flame
calcium- orange-red flame
copper-green flame

Question 9

reactions with sodium hydroxide

Answer 9

calcium-white
copper-blue
iron (II) -green
iron (III)- brown
aluminium- colorless
magnesium- white

Question 10

test for carbonates

Answer 10

adding dilute acid which produces carbon dioxide gas, turning the limewater cloudy

Question 11

test for halides

Answer 11

adding nitric acid then silver nitrate, producing a precipitate of silver halide:
chloride- white
bromide-cream
iodide-yellow

Question 12

test for sulfates

Answer 12

adding hydrochloric acid them barium chloride. Produces white precipitate of barium sulfate