The relative density of a liquid is 0.5. The density bottle weighs 200 g when filled with water and 120 g when filled with the liquid. The mass of density bottle is:
40 g
Let
Mass of empty density bottle = m
Mass of water filled in density bottle = mw
Mass of the liquid filled in density bottle = ml
Given:
m + mw = 200 g
m + ml = 120 g
Hence, mw−ml= 80 g ...(1)
Relative density of liquid = 0.5
Density bottle carries equal volume of liquids. Hence, volume of water and the liquid is same.
Relative density of liquid =
Density of liquidDensity of water= mlmw = 0.5
Hence, ml = 0.5 mw ....(2)
By solving equation (1) and (2) mw = 160 g
Given: m+ mw = 200 g
⟹m=200 g−160 g=40 g
Hence, mass of density bottle = 40 g