Question

The diagram below illustrates an experimental set up to compare relative amounts of a gas in inhaled air and exhaled air.

1. On the diagram, show with arrows the direction of movement of inhaled and exhaled air into and out of the mouth.
2. What is the name of the gas being investigated in the experiment 
3. What will happen to the lime water in. 
   Boiling tube A?
   Boiling tube B? 
4. Explain the observations made in (3) above.

Answer 1

1.  
   
2. carbon (IV)oxide;
3. Boiling tube A? - Boiling tube A  Lime water remains clear
   Boiling tube B? - Boiling tube B A white precipitate is formed.
4. In tube A the level of Carbon (IV) Oxide in inhaled air is low; compared to high amount of Carbon (IV) Oxide exhaled from the body; due to high rate of respiring cells;