Question
Chemistry Question on GROUP 1 ELEMENTS
Portland cement contains the following amount of CaO
A
5-15%
B
20-35%
C
50-60%
D
70-80%
Answer
50-60%
Explanation
Solution
Composition of Portland cement is as follows: Calcium oxide CaO 61.5% Silica SiO 22.5% Alumina Al O 3 7.5% Magnesium oxide MgO 2.5% Ferric oxide FeO 2.0% Potassium oxide KO 1.5% Sulphur trioxide SO 1.0% Sodium oxide NaO 1.5%