Concentrated solutions of HCl are corrosive and toxic.
Chemicals and Solutions
- 0.1 M HCl
- Methyl orange indicator solution
- 5 cylinders
- 100 ml graduated cylinder
- 10 ml grad. cylinder
- Buffer array of methyl orange indicator
- Stir rods
- pH meter and digital display
- Mark cylinders as follows: 0.1 M, 0.01 M, 10-3 M, 10-4 M, 10-5 M Hydrochloric acid.
- Fill the first cylinder (marked 0.1 M) with 100 ml of 0.1 M HCl.
- Measure 10 ml of 0.1 M HCl into 100 ml cylinder, dilute to 100 ml with distilled water.
- Repeat the above step, making a serial dilution, until all the concentrations have been made.
- Add methyl orange indicator to each concentration and compare color to the buffer array. Use the pH meter-digital display to take the pH of each concentration.
Hint: This demonstration can be used in conjunction with demonstration Weak Acids - pH of Acetic Acid.