Analytical Procedures - Acid Concentration (Mercury Solutions)
February 24, 2002

Introduction

Sulfuric acid is neutralized with sodium carbonate using methyl-orange as an indicator.

Equipment

• 250 ml Pyrex E-Flask
• 25 ml pipette
• 25 ml burette
• 50 ml drop flask

Reagents

• Methyl-orange solution (0.2%)
• Sodium carbonate solution (1 ml = 0.5 g H₂SO₄)

Procedure

Transfer a 25 ml filtered sample to a 250 ml E-Flask.  Add approximately 100 ml water and boil for 5 minutes to remove dissolved SO₂ content.  Add 2 to 3 drops of methyl-orange.  Titrate with sodium carbonate until the colour changes from orange to yellow.

Calculation

ml Na₂CO₃ x 0.05 x 1000 / 25 = g H₂SO₄/ l