•  Materials 
• Red litmus paper 
• Blue litmus paper 
• Codium hydroxide 
• Hydrochloride acid 
• Pipette 
• 4 Test tubes 

• Steps 

• Rip the litmus paper in half and put half in each test tuber . 

• Add 3 drops of hydrochloric acid to the blur litmus paper in test tube 1 

• Add 3 drops of hydroric acid to the red limus paper in test tube 2 

• Add 3 drops of sodium hydroxide to the blue limus paper in test tube 3 

• Add 3 drops of sodium hydroxide to the red litmus paper in test tube 4 

• Blue Litmus: no change it is an alkaline.

• Blue Litmus : changes to red it is an acid.

• Red Litmus: no change it is an acid.

• Red litmus: changes to blue it is an alkaline.