3781Chemical EngineeringMedium
Alumina, silica, lime and iron oxide are the basic raw material for the manufacture of Portland cement. The component of Portland cement which first hardens is________?
A3CaO. SiO2
B2CaO. SiO2
C5CaO. 3 Al2O3
D3CaO. Al2O3
Correct answer
C. 5CaO. 3 Al2O3
Explanation
The correct answer is 5CaO. 3 Al2O3.