Question

How many moles of ethanoic acid (CH3COOH) are formed when 39.99 g of ethanoyl chloride (CH3COCl , molar mass = 78.5 g/mol) are hydrolysed (assuming that the reaction went to completion)?

Answer 1

Given the mass of ethanoyl chloride (CH3COCl) taken = 39.99 g

Molecular mass of ethanoyl chloride (CH3COCl) = 78.5 g/mol

Hence moles of ethanoyl chloride (CH3COCl) taken = mass / molecular mass = 39.99 g / 78.5 g/mol = 0.509 mol

The balanced hydrolysis reaction of ethanoyl chloride (CH3COCl) can be written as

CH3COCl + H2O ----- > CH3COOH + HCl

1 mol, ------- 1 mol -------- 1 mol, -------- 1 mol

From the above balanced reaction it is clear that 1 mole of CH3COCl forms 1 mole of CH3COOH

i.e. moles of CH3COCl taken = moles of CH3COOH formed = 0.509 mole

Hence moles of CH3COOH formed = 0.509 mole (answer)