Elements, Compunds Mixtures

Question 1

Describe an element

Answer 1

An element is a substance at only contains one type of atom, and cannot be broke down into anything simpler by chemical means

Question 2

Describe an atom

Answer 2

The smallest particle of a chemical element, the building blocks of all life

Question 3

Describe a compound

Answer 3

A substance with two or more different elements chemically bonded together

Question 4

Describe a mixture

Answer 4

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

Question 5

Here is a list of substances:
Aluminium
Oxygen
Rock salt
Air
Calcium carbonate 

Sort them into elements, compounds and mixtures

Answer 5

Element
Element
Mixture
Mixture 
Compound

Question 6

Which separation technique would you use for sand and water?

Answer 6

Filtration

Question 7

State the separation method for oil and water

Answer 7

Separation funnel

Question 8

State the separation method for iron and sulfur

Answer 8

A magnet

Question 9

Name two disadvantages to using HPLC

Answer 9

It is very expensive and difficult to clean

Question 10

What is an advantage to mass spectrometry?

Answer 10

It’s fast

Question 11

Define solute, solvent and solution

Answer 11

Solute: a solid that dissolves in a liquid
Solvent: a liquid that dissolved a solid
Solution: the liquid formed when a solvent dissolves a solute

Question 12

Why is pencil used to draw in the lines on chromatograph paper?

Answer 12

Because the graphite in pencil is insoluble and won’t dissolve into the paper

Question 13

What is the general name for the solid found in filtration paper?

Answer 13

Residue

Question 14

What is the general name for the liquid found after using the filtration method?

Answer 14

Filtrate

Question 15

State two physical properties of metal

Answer 15

Shiny and malleable

Question 16

Which separation technique is used for ethanol and water?

Answer 16

Distillation

Question 17

What is distillation?

Answer 17

Distillation is the process that can be used to separate a pure liquid from a mixture of liquids. It works when the liquids have different boiling points.

Question 18

Name the sequence of events in distillation

Answer 18

Heating ~> evaporation ~> cooling ~> condensing

Question 19

What does immiscible mean? Give an example

Answer 19

It means the liquids don’t dissolve in each other e.g oil and water

Question 20

What are miscible liquids? How are they separated?

Answer 20

Liquids that are hard to separate as they have dissolved in on each other. They are separated by fractional distillation, as they have different boiling points

Question 21

What is the equipment used in chemistry in which Bunsen burners are lit beneath and usually hold evaporating dishes?

Answer 21

Tripod and gauze

Question 22

Predict the value you would expect for magnesium carbonate MgCO3

Answer 22

24 + 12 + (16 x 3)
36 + (16 x 3)
36 + 48
= 84

Question 23

Name the diatomic molecules

Answer 23

H2, N2, O2, F2, Cl2, Br2 and I2