Question

20ml of lubricating oil was dissolved in alcohol The solution was titrated against 0.1 N KOH solution. At the end point the burette reading was found to be 2. 5ml calculate the acid value of the oil.  ( density of oil= 0.86 g/ml)

Answer 1

Given data  :-    Normality of KOH   =   0. 1N

                               Volume of KOH  = 2.5 ml

                                Density of oil    = 0.86g/ml

                              Volume of oil      =  20m/.

To find  :-              Acid value of oil 

Formula  :-    Acid value =`("Vol. of KOH xx Normality of KOH xx 56")/("Weight of oil")`

Solution  :-              weight of oil = Density x Volume

                                                    = 0.86 x 20

                                                    = 17.2gms.

                         Acid value          =`("Vol of KOH xx Normality xx 56")/("Weight of oil")`

                                                    =`(2.5 xx 0.1 xx 56)/17.2`

                                                    = 0.814mg

∴  Acid value = 0.814 mg/ gm of the oil.