How to Test for Calcium Hydroxide

White vinegar can be used to test for many calcium compounds.
••• Hemera Technologies/ Images

Calcium hydroxide, commonly called slaked lime, is an inorganic compound with the chemical formula Ca(OH)2. This compound is a base and is widely used in industry--for example, as a cleaning agent. Identifying calcium hydroxide might be a chemistry class assignment that requires two tests. The first one measures the pH (acidity) of the calcium hydroxide solution to ensure it is basic. The second test, using a dilute solution of sulphuric acid, determines the presence of calcium ions.

    Pour about 5 milliliters of the solution to be tested into the beaker.

    Dip the strip of the pH paper strip into the solution and then take it out. The pH paper will change its color.

    Compare the color of the paper with the scale enclosed with the pH paper to assign the pH of the solution. A basic pH value such as 10 to 11 is indicative for calcium hydroxide.

    Fill a pipette with the sulphuric acid solution.

    Add five to ten drops of the solution from the pipette to the beaker.

    Observe the solution in the beaker: If a white precipitate forms, it indicates the presence of calcium ions; this reaction follows the equation Ca(OH)2 + H2SO4 = CaSO4 (precipitate) + 2H2O.

    Things You'll Need

    • Beaker
    • pH paper
    • Plastic pipette
    • Sulphuric acid solution (5 percent)


    • Wear gloves and goggles when handling hydrochloric acid.

Related Articles

How to Test for Sodium Bicarbonate
How to Dissolve Calcium Oxalate
How to Test for Acidity With Litmus Paper
How to Calculate Bicarbonate Concentration
How to Determine If Salts Are Acidic or Basic
Sulfuric Acid & Chlorine Bleach Reaction
How to Test for Potassium Iodide
How to Do Titration Calculations
How to Calculate the PH of NaOH
How to Extract Iodine From Potassium Iodide
How to Convert From Moles Per Liter to Percentage
How to Dissolve Magnesium Chloride
Characteristics of Aquatic Plants
How to Calculate Solubilities
How to Test for Hydrochloric Acid
How to Put Base Log on Graphing Calculator
How to Calculate the Normality of HCL
How to Find Mass Percentage
How to Calculate End Point
How to Find the Number of Ions in a Compound

Dont Go!

We Have More Great Sciencing Articles!