Question

Weight of 1 litre milk is `1.032 kg`. It contains butter fat (density `865 kg m^(-3))` to the extent of `4.0%` by wt`//`volume. Calculate the density of the fat -free skimmed milk.

Answer 1

Let `100 m^(3)` milk contains `4m^(3)` fat.
`:.` Weight of butter fat in `1 m^(3)` milk
`=(4)/(100)xx865= 35 kg`
Also Weight of `10^(3)cm^(3)` milk `=1.032 kg`
`:.` Weight volume of skimmed milk `= 1.0-0.04=0.96m^(3)`
`:.` Density of fat free skimmed milk`=(997)/(0.96)`
`=10 38.5 kg//m^(3)`