3E 2.4 Fire triangle - reagens

3E Chemistry task week 50-51
  • You can name the three conditions for combustion.
  • You can use the fire triangle to explain how to extinguish a fire.
  • You know what a reagent is.
  • You can explain how to demonstrate the presence of hydrogen, oxygen, water, carbon dioxide and sulfur dioxide.
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Slide 1: Slide
ScheikundeMiddelbare schoolhavo, vwoLeerjaar 3

This lesson contains 19 slides, with interactive quizzes and text slides.

time-iconLesson duration is: 45 min

Items in this lesson

3E Chemistry task week 50-51
  • You can name the three conditions for combustion.
  • You can use the fire triangle to explain how to extinguish a fire.
  • You know what a reagent is.
  • You can explain how to demonstrate the presence of hydrogen, oxygen, water, carbon dioxide and sulfur dioxide.

Slide 1 - Slide

This does not belong in the fire in the triangle:
fuel
oxygen
temperature higher than the ignition temperature
food
heat
cold
melting
density

Slide 2 - Drag question

How to extinguishing a fire
You now know which three factors are necessary the get a fire started.
If you want to extinguish a fire, you must remove one (or more) of these factors.
For each situation, you can examine which factor is easiest to remove and therefor determine which extinguishing method can be used.
For example, in the event of a fire caused by a gas leak, it is wise to first close the gas tap (remove fuel).

Slide 3 - Slide

Look at the sentences below about extinguishing a fire.
Drag the sentences to the side of the triangle that you have to remove.
Close the gas tap.
Extinguish a paper fire with water
Wrapping someone in a fire blanket.
Blow out a lighter.
Place the lid on the deep fryer.
Extinguish a gasoline fire with foam

Slide 4 - Drag question

A reagent is a substance that reacts in a characteristic, observable manner (sound or color) with the substance you want to demonstrate.

A reagent needs two meet two requirements:
Selective: the reagent only reacts to one (or little) substance(s)
Sensitive: little amount is required of both the reagent as 
                    the substance to be detected. 
There are some reagents you need to know about.


Reagent (plural: reagents)
NOTE
& LEARN

Slide 5 - Slide

Copy this scheme in your chemistry notebookschrift 

show
reagent/method
Observation
water
limewater
sulfur dioxide
glowing splint
flame
you hear a characteristic 'pop'
NOTE
& LEARN
You must complete this table with the help of the following slides.

Slide 6 - Slide

Watch the above (Dutch) videos to complete your table further. Good luck.

Slide 7 - Slide

Practise makes perfect.
Your table should be completely filled in.
Answer the following questions to see if your knowledge about reagents is complete enough. 
Improve your schedule if necessary.

Slide 8 - Slide

White copper sulphate is a ... to demonstrate the presence of ... .
A
reagent, carbon dioxide
B
reagent, hydrogen
C
reagent, water
D
reagent, oxygen

Slide 9 - Quiz

A reagent that detects only one or very few different substances is called ....
A
sensitive
B
sensible
C
selective
D
obvious

Slide 10 - Quiz

Which statements are true?
1) A reagent must be sensitive and therefore must react
with a little bit of the substance
2) A reagent must be selective and therefore it must only react
with itself
A
A and B are true
B
A is true, B is not true
C
A is not true, B is true
D
A and B are not true

Slide 11 - Quiz

The presence of oxygen can be shown by:
A
collect the gas in a test tube and hold the opening near a flame you hear a 'pop'
B
collect the gas in a test tube and hold a glowing splint in the test tube, the splint will glow brighter

Slide 12 - Quiz

The 'pop' that you hear is evidence of the presence of
A
carbon dioxide
B
hydrogen
C
oxygen
D
water

Slide 13 - Quiz


The flask contains lime water. A second substance is sucked through the lime water. Which substance can you detect with lime water?
A
Water
B
Carbon dioxide
C
Oxygen
D
None of the three options

Slide 14 - Quiz

You can show the presence of carbon dioxide with lime water. What happens to the limewater when it reacts with carbon dioxide?
A
It's going to solidify
B
It becomes yellow and cloudy
C
It becomes a clear liquid
D
It becomes cloudy white

Slide 15 - Quiz

What is the reagent of SO2?
A
iodine solution
B
white copper sulphate
C
lime water
D
starch

Slide 16 - Quiz

Which reagent is used to demonstrate:
oxygen
carbon dioxide
water
hydrogen
sulfur dioxide
clear lime water
white copper sulphate 
glowing splint
flame
iodine solution

Slide 17 - Drag question

What observation do you do when demonstrating:
oxygen
carbon dioxide
water
hydrogen
sulfur dioxide
clear colorless liquid turns white cloudy
white solid becomes a blue solid
will glow brighter
flame
clear yellow liquid becomes clear colorless liquid

Slide 18 - Drag question

All done?!
Please upload a picture of your reagent tabel at the 'opdracht' in google classroom.

Slide 19 - Slide