Question

The density of liquid A is 1.6 g cm-3 and its height h(A) = 16.9 cm, then the density of oil B of height h(B) = 30 cm in the U-tube is about

(a) 0.90 g/cm3

(b) 1.12 g/cm3

(c) 2.24 g/cm3

(d) 3.54 g/cm3

I have been asked this question in an interview for internship.

The query is from Pressure and Hydrostatic Head-II in section Introductory Concepts of Chemical Process Calculation

Answer 1

The correct choice is (a) 0.90 g/cm3

To elaborate: Pressure at point ‘b’ = Atmospheric pressure + ρB ghB

Pressure at point ‘a’ = Atmospheric pressure + ρAghA

Pressures at point ‘a’ = point ‘b’.