If 36.10 mL of 0.223 M of NaOH is used to neutralize a 0.515 g sample of citric acid, what is the molar mass of the acid?
The molar mass of the citric acid is
The balanced chemical equation for the neutralization reaction that takes place between sodium hydroxide,
Since you know the molarity and the volume of the
Now use the aforementioned mole ratio to see how many moles of citric acid were present in 0.515 g
Now simply divide the mass of citric acid given by the number of moles it contained to get the compound's molar mass
Rounded to three sig figs, the number of sig figs given for 0.515 g, the answer will be
SIDE NOTE The actual molar mass of citric acid is 192.12 g/mol, so your result is in agreement with the known value.