Question

1. Explain why a titration can be used to determine the percent by mass of acetic acid in the vinegar and the molecular mass of an unknown acid?

2. Why would it be important to know the molecular mass of an unknown acid in the experiment?

Answer 1

Q1.

we can relate via --> base/acid titration

if we know how much moles of titrant we added, then we can relate stoichoimetrically

i.e.

1 mol of base = 1 mol of acid

and we know that for mass %

mass of acid % = mass of acid / Total mass * 100%

total mass = mass of solution

mass of acid = mol of acid * MW of acid

that's why we need Molar Weight of Acid

so

we need:

- Volume of titrat --> relate to moles of acid

- Molar Weight of acid --> change to mass

- Calcualte % mass