Topic 2: Elements, Compunds and Mixtures

Question 1

What is the definition of an element?

Answer 1

An element is a substance that consists of only one type of atom. Elements cannot be broken down into simpler substances by chemical means

Question 2

What is the definition of a compound?

Answer 2

A compound is a substance that consists of two or more different elements chemically joined together

Question 3

What is the definition of a mixture?

Answer 3

A mixture consists of two or more substances that are usually easy to separate

Question 4

Aluminium: Element, Compound or Mixture?

Answer 4

Element

Question 5

Sodium chloride (salt): Element, Compound or Mixture?

Answer 5

Compound

Question 6

Carbon dioxide: Element, Compound or Mixture?

Answer 6

Compound

Question 7

Lead: Element, Compound or Mixture?

Answer 7

Element

Question 8

Rock salt: Element, Compound or Mixture?

Answer 8

Mixture

Question 9

Sugar solution: Element, Compound or Mixture?

Answer 9

Mixture

Question 10

What does soluble mean?

Answer 10

A solid that dissolves easily in a liquid solvent eg. Sugar, salt

Question 11

What does insoluble mean?

Answer 11

A solid that does not dissolve easily in a liquid solvent eg. Sand

Question 12

What does solute mean?

Answer 12

A solid that dissolves. This is a substance that changes its state during a dissolving process

Question 13

What does solvent mean?

Answer 13

This is a substance that does not change its state during a dissolving process

Question 14

What does solution mean?

Answer 14

A mixture containing the solute and solvent

Solution = solute + solvent

Question 15

What does residue mean?

Answer 15

Solid particles trapped in filter paper eg. Sand

Question 16

What does filtrate mean?

Answer 16

Liquid particles that pass through the filter paper

Question 17

What does distillate mean?

Answer 17

The liquid that condenses during distillation and is collected

Question 18

What does miscible mean?

Answer 18

A liquid that mixes easily in another liquid eg. Ethanol and water

Question 19

What does immiscible mean?

Answer 19

A liquid that does not mix easily in another liquid eg. Oil and water

Question 20

What are the benefits of mass Spectroscopy?

Answer 20

> Fast analysis
Results can be linked to database to
identify substance

Question 21

What are the drawbacks of using Mass Spectroscopy?

Answer 21

> Expensive equipment
Presence of isotopes leads to more than
one peak

Question 22

What are the benefits of using HPLC?

Answer 22

> Fast
Accurate
Use only minute samples

Question 23

What are the drawbacks of using HPLC?

Answer 23

> Sample must be a liquid

> Expensive

Question 24

What is the equation for working out relative atomic mass?

Answer 24

Mass x abundance / total abundance

eg. (20 x 10) + (80 x 11) / 100 < (always the
total)

Question 25

Is milk a mixture or a compound?

Answer 25

A mixture

Question 26

Is ice a mixture or a compound?

Answer 26

A compound

Question 27

Is orange juice a mixture or a compound?

Answer 27

A mixture

Question 28

Is air a mixture or a compound?

Answer 28

A mixture

Question 29

Is paint a mixture or a compound?

Answer 29

A mixture

Question 30

Fractional distillation would be used to separate…

Answer 30

…two liquids with different boiling points

Question 31

Water is not suitable for dissolving in water. This means that oil is….

Answer 31

….immiscible in water