Heating octane

Heating octane

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Further Resources
This task is about changing states of matter: solid, liquid and gas.
A heating curve is a graph that represents the stages of matter that a substance changes into as heat is added to it. The flat lines on the curve mark where the stages of matter change. The temperature is constant at these transition points.
 
This is the heating curve of octane (the main component in petrol).
graph showing the heating curve of octane
a) i)
What is the temperature of the octane at the start of the investigation? __________°C
  ii)
Is the state of the octane a solid, liquid, or gas at the start of the investigation?
 
_______________
 
b)
At what temperature does the octane begin melting? __________°C
 
c)
At what temperature does the octane begin boiling? __________°C
 
d)
What two states would you observe at point A?
 
1. ____________________                    2. ____________________
 
e)
What state would you observe at point B? ____________________
 
f)
What two states would you observe at point C?
 
1. ____________________                    2. ____________________
 
g)
Describe what is happening to the particles when the octane becomes liquid. The particles:   
 
 
 
h)
Describe what is happening to the particles when the octane is rapidly boiling. The particles:
 
 
Task administration: 
This task can be completed with pencil and paper.
Level:
5
Curriculum info: 
Science, Communicating in science, Material World
Keywords: 
changes, particle nature of matter, heating curve, octane, graph interpretation, boiling point
Description of task: 
Students are provided with a graph of the heating curve for octane. Students use this to answer questions about state, temperatures, and changes of state.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
 
Capability: Interpret representations
This resource provides opportunities to discuss:
  • noticing patterns in data shown in a graph.
  • the role that science knowledge plays in being able to interpret a graph.
 
Science capabilities: 
Interpret representations
Answers/responses: 
   Y10 (11/1997)
a) i) –90 (± 5)
ii) Solid		 very easy
very easy
b) –55 (± 5) moderate
c) 125 (± 5) moderate
d) Solid and liquid difficult
e) Liquid difficult
f) Liquid and gas difficult
g) Liquid octane – particles are close together and moving around. very difficult
h) The particles are moving fast enough to be a gas. The attraction between the particles is broken down and the liquid changes to a gas. very difficult