ODWS logoThe Open Door Web Site

Breathing in the Air : The Lungs

Reference chapter

Question 2
HTML version
PDF version

The arrows in the diagram below show how air passes through the apparatus.

Apparatus

Questions

1. The liquid in the flasks is called lime water. At the beginning of the experiment it is clear. What does the lime water indicate if it:

2. If you breathed through this apparatus for a few minutes what would you expect to see happening in Flask A and Flask B?

3. Which of the two flasks has inspired air passing through it?

4. What does this experiment tell us about inspired air compared with expired air?

A good test for oxygen is to try to burn a candle in a sample of of an unknown gas. Oxygen is a gas which supports combustion (burning). If a candle is put into a gas jar containing pure oxygen it will burn for many minutes very brightly. The following experiment was carried out to test the combustion of the air breathed in and out by a man.
To gas jars were taken. Air from the atmosphere was trapped in one and air exhaled from a man's lungs was collected in the other.

Atmospheric air
Atmospheric air

Exhaled air


Candles

The candle burns for 30 seconds in A
The candle burns for 4 seconds in B

5. What do these results tell us about the amount of oxygen in the two jars?

6. What does our body do to the air that we breathe in and out? (Explain the difference in the percentage of gases in inhaled and exhaled air).

Homepage

IB Biology Web

Biology Homepage

Topic Chapters

Facts and Figures

Laboratory Work

Questions and Quizzes Index

> Questions and Quizzes

Listings, Recognitions and Awards

EABJM Public Web Site

© The Open Door Team
Any questions or problems regarding this site should be addressed to the webmaster

© Paul Billiet & Shirley Burchill 2014