C8

Question 1

pure substance

Answer 1

only contains 1 compount or element throughout

Question 2

how to test purity of sample

Answer 2

measure melting + boiling points -> compare with melting + boiling point of pure substance
closer measured value is to actual melting/boiling point, purer the sample is

Question 3

formulation

Answer 3

useful mixture with precise purpose, made by following go a formula
eg. paint, fuels, in drugs

Question 4

two phases of chromatography

Answer 4

mobile phase - moelcules can move, always liquid or gas

stationary phase - molecules cant move, can be solid or thick liquid

Question 5

test for chlorine

Answer 5

bleaches damp litmus paper - turns white

Question 6

test for oxygen

Answer 6

relight glowing splint

Question 7

test for carbon dioxide

Answer 7

bubbling with limewater turns solution cloudy

Question 8

test for hydrogen

Answer 8

“squeaky pop” from lit splint
(hydrogen burns quicky with oxygen to form H2O)

Question 9

mobile phase of paper chromatography

Answer 9

solvent

Question 10

sationary phase of paper chromatography

Answer 10

chromatography paper

Question 11

Rf value =

Answer 11

distance travelled by substance / distance travelled by solvent