Seperation Of Mixtures

Question 1

Element

Answer 1

A substance that has only one type of atom- they are pure.

Question 2

Compound

Answer 2

Two or more different atoms that are chemically bonded

Question 3

Mixture

Answer 3

Two or more different substances that are not chemically bonded

Question 4

Molecule

Answer 4

Two or more non - metals that are chemically bonded - don’t have to be differenr

Question 5

Soluble

Answer 5

A solid that can dissolve into a solvent

Question 6

Insoluble

Answer 6

A solid that can’t dissolve into a solvent

Question 7

Solution

Answer 7

When a solute dissolves in a solvent

Question 8

Solvent

Answer 8

A liquid that something can dissolve into

Question 9

Miscible

Answer 9

Liquids that can mix with a solvent

Question 10

Immiscible

Answer 10

Liquid that cannot mix with another solvent

Question 11

Solubility

Answer 11

Amount / mass of a solid which can dissolve in 100 grams of water at a specific temperature

Question 12

How would you separate sand from water?

Answer 12

Filtration

Conical flask

Question 13

Why can you use filtration to separate sand from water but not salt?

Answer 13

The sand is not soluble in water meaning that there is lots of residue left over. This can easily be filtered out. In salt and water, the salt dissoles into the water meaning that it cannot be filtered out.

Question 14

Impure

Answer 14

Made from more than one type of atom

Question 15

Distillation

Answer 15

For separation liquids for liquids

Thermometer
Cold water out
Cold water in

Question 16

Equation for rf value

Answer 16

Rf = distance travelled by compound / distance travelled by solvent
Must be between zero and one
NOTE: When describing how the dye has separated up the chromatogram, you must refer to the different heights that the SPOTS have traveled, not the dyes or the inks.

Question 17

Crystallisation

Answer 17

A soluble solid from a liquid . is used to produce solid crystals from a solution. When the solution is warmed, some of the solvent evaporates leaving behind a more concentrated solution.

1. A solution is placed in an evaporating basin and heated with a Bunsen burner.
2. The volume of the solution has decreased because some of the water has evaporated. Solid particles begin to form in the basin.
3. All the water has evaporated, leaving solid crystals behind

Question 18

Filtration

Answer 18

An insoluble solid from a liquid

Question 19

Chromatography

Answer 19

Different solutes in a coloured ink

Question 20

The liquid from a soluble solid

Answer 20

Distillation

Question 21

Pure substances and impure substances

Answer 21

Pure Have a fixed melting point and boiling point
Impure (mixtures) melt over a range of temps

Question 22

Simple distillation

Answer 22

is used to separate a solvent from a solution. It is useful for producing water from salt solution. Simple distillation works because the dissolved solute has a much higher
boiling point than the solvent. When the solution is heated, solvent vapour evaporates from the solution. The gas moves away and is cooled and condensed. The remaining solution becomes more concentrated in solute as the amount of solvent in it decreases

Question 23

Fractional distillation

Answer 23

Fractional distillation is used to separate different liquids from a mixture of liquids. It is useful for separating ethanol from a mixture of ethanol and water, and for separating different fractions from crude oil.Fractional distillation works because the different liquids have different boiling points.