C13- Chemical Analysis

Question 1

What is a pure substance?

Answer 1

A substance containing only one element

Question 2

What is the difference between the melting point and boiling points of pure and impure substances?

Answer 2

Pure- one specific temperature
Impure- occur across a range of temperatures

Question 3

What is a formulation?

Answer 3

A mixture of specific quantities of substances for a specific purpose

Question 4

What are examples of formulations? (7)

Answer 4

Fuels, cleaning agents, paints, medicines, alloys, fertilisers, foods

Question 5

What is chromatography?

Answer 5

A process to separate different components in a mixture of soluble substances

Question 6

How is Rf value calculated?

Answer 6

Rf= distance moved by substance/ distance moved by solvent

Question 7

What is the test for hydrogen?

Answer 7

Hold a lit splint near the gas
Gives a squeaky pop

Question 8

What is the test for oxygen?

Answer 8

Hold a glowing splint near the gas
Relights

Question 9

What is the test for chlorine?

Answer 9

Hold damp blue litmus paper near the gas
Will bleach it white

Question 10

What are the phases in chromatography?

Answer 10

Mobile- solvent
Stationary- paper

Question 11

What is the solvent front?

Answer 11

The top of where the solvent travels to

Question 12

What will more soluble substances do in the solvent?

Answer 12

Travel further

Question 13

What does pure substance do on a chromatogram?

Answer 13

Produce one spot