7E Mixtures and separation

Question 1

In a solution, which part is the solvent?

Answer 1

The solvent is the liquid part of a solution.

Water is often the solvent in a lot of solutions.

Question 2

What does it mean if a spot of dark ink on a chromatogram separates into 3 dots?

Answer 2

Iif a spot of dark ink on a chromatogram separates into 3 dots it means that it was made up of 3 other coloured inks.

Question 3

What do we mean by boiling?

Answer 3

When a liquid boils, all the liquid is trying to turn into a gas at the same time. Boiling happens at the liquid’s boiling point. Gas formed inside the liquid makes bubbles that rise to the surface.

Question 4

What is the boiling point of pure water?

Answer 4

The boiling point of pure water is 100 °C.

Question 5

If something is soluble, what does this mean?

Answer 5

Soluble means that something will dissolve.

Sugar is soluble in water.

Question 6

There are many different types of mixture. What is a solution?

Answer 6

A solution is a mixture where the solids break up into such small pieces that they are not visible, and the mixture is transparent.

Question 7

What is a solution?

Answer 7

A solution is a mixture of a solid dissolved in a liquid.

Question 8

How would you extract pure water from a salt solution (assuming that you want to keep the water)?

Answer 8

You would extract pure water from a salt solution by distillation (evaporation followed by condensation) using a liebig condenser.

Question 9

If you find the mass of a liquid (solvent) and a solid (solute) iand mix them so the solid all dissolves will the mass change?

Answer 9

No the total mass of the solution equals the mass of solvent added to the mass of solute. Nothing has actually vanished but the solid has broken into such tiny pieces that you cannot see it any more.

Question 10

How would you extract salt from a salt solution?

Answer 10

You would extract salt from a salt solution by evaporating the liquid in an evaporating basin on a tripod or leave it on a window sill for the sun to dry out.

Question 11

How could you increase how much solute dissolves in a solution?

Answer 11

Heat the solution.

Question 12

What is the method to seperate different solvents from a solution?

Answer 12

Distillation

Question 13

How could you separate the colours found in ink?

Answer 13

You could separate the colours found in ink using chromatography.

Question 14

What do we mean by solubility?

Answer 14

The solubility of a solute is the amount that will dissolve in a fixed amount of solvent at a particular temperature.

Question 15

What do we mean by evaporation?

Answer 15

Evaporation is when a liquid turns to a gas at its surface. It happens at any temperature. but is faster when the temperature is higher.

Question 16

What is the method to seperate a number of different solutes in a solution?

Answer 16

Chromatography

Question 17

If something is insoluble, what does this mean?

Answer 17

Insoluble means that something will not dissolve.

Sand is insoluble in water.

Question 18

Describe how you would separate a mixture of sand and water.

Answer 18

Use a filter funnel and filter paper to separate the mixture of sand and water by filtering.

Question 19

In a solution, which part is the solute?

Answer 19

The solute is the solid that has been dissolved.

In a solution of salty water the solute is the salt.

Question 20

What 2 processes make up distillation?

Answer 20

Distillation contains 2 processes, evaporation followed by condensation

Question 21

What is the name of the apparatus which is used to seperate out water from ink?

Answer 21

Liebig Condenser

Question 22

What is a mixture?

Answer 22

A mixture is when 2 substances are mixed but not chemically joined, and can be separated.

Question 23

What does insoluble mean?

Answer 23

Substances that do not dissolve in a solvent are insoluble

Question 24

How can chromatograms help to identify substances in a mixture?

Answer 24

Chromatograms can help to identify substances in a mixture because the substances always travel the same distance in the same solvents and give a characteristic repeatable pattern which can be recognised by scientists..

Question 25

What do we mean by a saturated solution?

Answer 25

If you keep adding solutes to a solvent, you will get to a point where no more will dissolve. The solution is saturated with solute.