N5 Chemistry St. Ninian’s High School
N5 Chemistry: Whole Course REVISION
Lesson 11 – Graphs
By the end of this lesson you should have revised:
1. How to choose an appropriate graph given a set of data.
2. How to create a graph and achieve full marks
You will have been successful in this lesson if you:
1. Watch the links provided
2. Complete revision questions provided
3. Complete and submit homework assigned
There is also a further reading section to help you gain more depth of
understanding for this section.
If you have any questions about the content of this lesson, you should ask your
class teacher either through your class MS team or via email. MS Teams will be
monitored throughout the week by a chemistry teacher. If you need help or
clarification with either the task or the content of the lesson, just ask.
You may wish to revise the following to help you understand this lesson:
- N5 Unit 2: Homologous Series
You do not need to copy any notes as this is all revision, but you
should complete all questions and tasks as outlined in this document.
Watch this video first:
https://youtu.be/qO2vwCKnUp8
Learning Outcomes
Success Criteria
Links to Prior Knowledge
N5 Chemistry St. Ninian’s High School
Graphs
Graphs can be created to show information in a different way.
The type of graph you use depends on the type of data you have.
Discrete Data
This data is normally given as numbers and words.
e.g. the different types of pets owned by pupils in a classroom
Type of Pet
Number of Pupils that
Dog
5
Cat
8
Fish
4
Rabbit
3
This data is best represented by bar charts or pie charts.
Continuous Data
This data is normally given as number and numbers.
e.g. the effect of changing temperature on the time a reaction takes
Temperature (°C)
Time (s)
10
90
20
75
30
62
40
51
50
45
This data is best represented by a line graph or scatter graph.
You do not need to be able to define these types of data but you should be
able to identify them and then select the correct graph to represent this data.
N5 Chemistry St. Ninian’s High School
The two main types of graphs you will be expected to use are:
Scatter Graphs
(straight or curved line of best fit)
- continuous data (numbers and numbers)
- Looking for a relationship (trend) between the two variables
- The independent variable (the one you change) goes on the x-axis.
The dependent variable (the one you measure) goes on the y-axis.
Example: The table below gives information about the solubility of sulfur
dioxide.
Temperature (⁰C)
18
24
36
42
48
Solubility (g/100 cm
3
)
11.2
9.2
6.5
5.5
4.7
N5 Chemistry St. Ninian’s High School
Bar Charts
- Discrete data (words and numbers).
- Categories go on the x-axis
Number values go on the y-axis.
- Bars should be equal width and evenly spaced out.
Example: The numbers of each type of pets owned by a class.
Type of Pet
Number of Pets
Dogs
7
Cats
6
Goldfish
4
Birds
2
Hamsters
3
N5 Chemistry St. Ninian’s High School
Line Graphs
Line graphs can also be drawn but this is less commonly asked for.
- Continuous data (numbers and numbers)
- looking for a relationship between each individual pair of points
- each plot is joined.
Example: The table below gives information about midday temperature
over 6 days.
Day
Midday Temperature (⁰C)
1
25
2
28
3
22
4
19
5
23
6
27
N5 Chemistry St. Ninian’s High School
Marking Schemes
Graphs are awarded 4 marks in an assessment:
Selecting the correct type of graph 1 mark
Axes of graph has suitable scales 1 mark
Axes of the graph have suitable labels and units 1 mark
Data points are plotted accurately with either a
line of best fit drawn or plots joined
Or 1 mark
Heights of bars are plotted accurately
Now work through the PowerPoint: ‘Spot the Mistake – Graphs’
You can access it in the ‘Whole Course Revision, week 1’ folder in
the Team Files
N5 Chemistry St. Ninian’s High School
Complete the following questions in your class work jotter.
The answers will be posted on Teams later in the week.
Practice Questions - Graphs
Create appropriate graphs for the following pieces of data.
1. The table below shows the density of different metals.
(4)
2. The table shows the relationship between temperature of the water and
the amount of dissolved oxygen.
Temperature of
water (
o
C)
0
20
40
60
70
80
Concentration of
dissolved oxygen
(g/cm
3
)
70.8
44.2
31.6
23.4
19.5
14.7
(4)
Total: 8 marks
Metal
Density (g cm
-3
)
Aluminium
Copper
Iron
Magnesium
Sodium
2.7
9.0
7.9
1.7
1.0
N5 Chemistry St. Ninian’s High School
Past-Paper Questions - Graphs
Past-Paper
Questions
2015
Section 2 – Qu 1b
2018
Section 1 – Qu 1b
2019
Section 3 – Qu 3cii
N5 Chemistry St. Ninian’s High School
To learn more about graphs, try the following online resources:
BBC Bitesize: https://www.bbc.co.uk/bitesize/guides/zc7sb82/revision/2
https://www.bbc.co.uk/bitesize/guides/zc7sb82/revision/5
Scholar: Log in through GLOW
National 5 Chemistry
Chemistry in Society
Topic 8 Chemical
Analysis
8.5 Reporting Experimental work
8.5.2 Graphs
8.5.2.1 Bar Graphs
8.5.2.2 Scatter Graphs
Further Reading