C12.1-C12.3 (Pure Substances and Mixtures, Chromotography, Testing For Gases

Question 1

Test for hydrogen

Saftey

Answer 1

A lighted splint pops

Wear eye protection. Hydeogen is flammable

Question 2

Test for oxygen

Safety

Answer 2

A glowing splint relights

Wear eye protection

Question 3

Test for Carbon Dioxide

Saftey

Answer 3

Limewater turns clear to milky, cloudy white

Wear eye protection

Question 4

Test for Chlorine

Saftey

Answer 4

Damp litmus paper turns blue to white, as it gets bleached (may turn red at first if acidic)
(Chlorine is a toxic gas, handle with care)

Question 5

Pure substance

Answer 5

A substance that is made up of just one substance (which can either be an element or compound)

Question 6

What are the fixed points of a compound or element

Answer 6

Its boiling and melting points

Question 7

What’s an impure substance

Answer 7

A mixture of 2 or more different elements or compounds

Question 8

What can be looked at to identify wether a substance is pure or not

Answer 8

Pure has a specific fixed points

Impure melts or boils over range of temperatures

Question 9

What are formulations

Answer 9

Useful mixtures, made up definite proportions, designed to give a product the best properties possible to carry out its function

Question 10

How can you analyse unknown substances within a solution

Answer 10

Paper Chromatography

Question 11

Rf equation

Retention factor

Answer 11

Distance moved by substance / distance moved by solvent

Question 12

What can Rf values be measured and match to?

Answer 12

Matched against databases to identify specific substances