Question

The average molecular weight of the triglycerides (use 14(g) of mass) in coconut oil is 680 g/mol. How much NaOH (in grams) is required to completely saponify this oil?

Answer 1

moles of triglycerides = mass / molar mass = 14 g / 680 g/mol = 0.0206 mol

let see the equation

triglyceride + 3NaOH ---> products

triglyceride means three ester groups in the molecule

each mol of ester functional group required 1 mol NaOH molecules accordingly three mol of ester functional groups required 3 mol of NaOH

so

one mol of triglycerides having 1 mol of naOH

accordingly

0.0206 ml of triglyceride required 3 x 0.0206 mol = 0.062 mol

mass of NaOH = moles of NaOH x molar mass of NaOH = 0.62 mol x 40 g/mol

= 2.47 g of NaOh