0.075 g of a monobasic acid required 10 mL of `N//12 NaOH` solution for complete neutralisation. Calculate the molecular mass of the acid

Explanation

Mass of the organic acid taken = 0.075 g
Volume of `N//12 NaOH` required for neutralisation = 10 mL
step I. Calculation of equivalent mass of the acid.
`10 mL` of `N//12 NaOH -= 0.075 g` of acid
`:.` 1000 mL of `1N NaOH = ((0.075 g) xx (1000 mL) xx (1N))/((10 mL) xx (N//12)) = 90 g`
1000 mL of 1 N NaOH solution contain one gram equivalent of base and it reacts with one gram equivalent of the acid.
`:.` Equivalent mass of the acid = 90
step II. Calculation of the molecular mass of the acid.
Molecular mass = Equivalent mass `xx` Basicity
`= 90 xx 1 = 90` [Foe a monobasic acid, basicity = 1]