Q. In curing cement plasters water is sprinkled from time to time. This helps in
A) Keeping it cool
B) Developing interlocking needle-like crystals of hydrated silicates
C) Hydrating sand and gravel mixed with cement
D) Converting sand into silicic acid
Explanation
(b)
$CaSO_{4}\ .\frac{1}{2}H_{2}O\ + 1\frac{1}{2}H_{2}O\ \overset{\ \ \ \ \ \ Setting\ \ \ \ \ \ }{\rightarrow}$
$CaSO_{4}\ .\ 2H_{2}O\ \overset{\ \ \ \ \ Hardening\ \ \ \ \ \ \ }{\rightarrow}\ CaSO_{4}\ .\ 2H_{2}O$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.