Question

away from normal?
(b). An object placed at a distance of 36cm from a convex lens forms an image at a distance of
24cm from the lens. Find the fical length of the lens.
2. (a). What is plaster of paris? How is it prepared? Write chemical equation of the reaction​

Answer 1

Answer:

2. ans.

Plaster of Paris also known as P.O.P. is a chemical compound with a chemical formulae of CaSO4. 1/2 H2O.

It contains water of crystallization.

It is prepared by heating of gypsum,

when gypsum is heated at 373 K, formation of P. O. P. takes place...

CaSO4. 2H2O ——> CaSO4. 1/2 H2O

hope it helps you...