C2.1 separating mixtures

Question 1

What is a pure substance

Answer 1

Pure substances only contain one element or compounds.

Have a fix melting point

Question 2

How could you tell of the substance was impure

Answer 2

Arrange of melting temperatures. Melting point lower than original pure substance melting point

Question 3

List the 6 types of separating methods

Answer 3

Simple distillation fractional distillation chromatography filtration evaporation crystallisation

Question 4

Filteration

Answer 4

Separating an insoluble substance from a liquid eg water and sand

Question 5

Crystilisation (soda son)

Answer 5

Separating a solid from a solution eg sodium chloride from salt water

Question 6

Simple distillation

Answer 6

Separating a solvent from a solution. Eg Pure water from salt water

Question 7

Fractional distillation

Answer 7

Separating a mixture of liquids with different boiling points

Question 8

Chromatography

Answer 8

Separating substances that move at different rates through a medium

Question 9

Rf values

Answer 9

The ratio of the distance move by compound to the distance moved by solvent

Distance travelled by substance / distance travelled by solvent

Question 10

What does the relative formula mass

Answer 10

The element times by how many times is there.

For example O3 Would be 16×3

Question 11

What is empirical formula

Answer 11

Simplest whole number ratio of atoms in a compound

C4 H10= c2 h5