Procedure

a) Preparation of Cement Solution:

1. Weigh approximately 1 g of the cement sample accurately using an analytical balance.
2. Transfer the sample to a beaker and add 20 mL of dilute hydrochloric acid (HCl).
3. Heat the mixture gently on a hot plate until the cement dissolves completely.
4. Filter the solution to remove any insoluble residue and collect the filtrate in a clean beaker.

b) Determination of Calcium Oxide (CaO):

1. Add ammonium hydroxide (NH₄OH) dropwise to the filtrate until the solution is slightly alkaline (pH ~8-9).
2. Add 10 mL of ammonium oxalate ((NH₄)₂C₂O₄) solution to precipitate calcium oxalate.
3. Filter the precipitate, wash it with distilled water, and dry it in an oven at 110°C.
4. Weigh the dried precipitate and calculate the percentage of CaO using stoichiometric relationships.

c) Determination of Silicon Dioxide (SiO₂):

1. Acidify a portion of the filtrate with dilute nitric acid (HNO₃).
2. Evaporate the solution to dryness to convert silica into insoluble SiO₂.
3. Filter, wash, dry, and weigh the residue to determine the percentage of SiO₂.

d) Determination of Iron Oxide (Fe₂O₃) and Aluminum Oxide (Al₂O₃):

1. To another portion of the filtrate, add ammonium hydroxide (NH₄OH) until a precipitate forms.
2. Filter the precipitate, which contains Fe(OH)₃ and Al(OH)₃.
3. Dissolve the precipitate in dilute HCl and determine Fe₂O₃ and Al₂O₃ using volumetric titration with potassium permanganate (KMnO₄) and sodium hydroxide (NaOH), respectively.

e) Determination of Magnesium Oxide (MgO):

1. Use the remaining filtrate to precipitate magnesium ammonium phosphate (MgNH₄PO₄) by adding ammonium phosphate ((NH₄)₂HPO₄).
2. Filter, dry, and weigh the precipitate to calculate the percentage of MgO.