Topic 8 - Chemical Analysis

Question 1

what is purity defined by in chemistry

Answer 1

a substance that only contains one compound or element.

Question 2

how to test if a substance is pure

Answer 2

by measuring its melting and boiling point and comparing to a data book

Question 3

what is a formulation

Answer 3

they are useful mixtures with a precise purpose that are made by following a formula

Question 4

what are the two phases in chromatography

Answer 4

stage one; mobile phase - where molecules can move. always a liquid or gas
stage two; stationary phase - where molecules cant move. this can be a solid or thick liquid.

Question 5

summary of how chromatography works

Answer 5

the more time spent in mobile phase than stationary phase then the higher it will be.

Question 6

how to test for chlorine and what colour it goes to

Answer 6

chlorine bleaches damp litmus paper. it turns white

Question 7

how to test for oxygen and what colour it goes to

Answer 7

put a glowing splint in test tube. if it relights then oxygen is present

Question 8

how to test for carbon dioxide and what colour it goes to

Answer 8

carbon dioxide will turn cloudy when put in an aqueous solution of calcium hydroxide (limewater)

Question 9

how to test for hydrogen and what colour it goes to

Answer 9

if you put a lit splint at the open end of a test tube containing hydrogen it will make a pop