Emulsification of 10 ml of oil in water produces 2.4 × 1018 droplets. If the surface tension at the oil-water interface is 0.03 Jm–2 and the area of each droplet is 12.5 × 10–16 m2 , the energy spent in the formation of oil droplets is-
(A) 90 J
(B) 30 J
(C) 900 J
(D) 10 J
Correct Option :- (A) 90 J
Explanation :-
Total droplets = 2.4 × 1018
total area = total droplets × area of one drop
= 2.4 × 1018 × 12.5 × 10–16
= 12.5 × 2.4 × 102 m2
Energy consumption
= 0.03 × 12.5 × 2.4 × 102
= 90 Joule
