Question

a vinegar sample contains 2.00 x 10^-3 moles of acetic acid. if a 4.00 g sample of vinegar was used in titration, calculate the percent by mass of this vinegar solution. Answer should be given to the correct number of significant figures.

Answer 1

Molar mass of acetic acid = 60.05 g/mol
mass of acetic acid = number of moles * molar mass
                    = 2.00 * 10^-3 * 60.05
                   = 0.1201 g
                  
Mass % of acetic acid = mass of acetic acid * 100 / total mass
                      = 0.1201*100 / 4.00
                      = 3.00 %
Answer: 3.00 %