The label on a bottle of vinegar says that the vinegar is 4% acetic acid. What would be the molarity of the acetic acid in solution

Molarity = 3.018 M

Explanation:

Density = Mass / Volume

which means that

Volume x Density = Mass

So ... for the liquid in the bottle we have that

750 ml x 1.006 g / ml = Mass

750 * 1.006 g = 754.5 g this is the mass of the liquid

And the acetic acid is 4% of this value dissolved.

So, the mass of the acetic acid will be

0.04 x 754.5 = 30.18 g

Molarity = (30.18 / 1000) = 3.018 M

Density = Mass / Volume ... which means that ...

Volume * Density = Mass

So ... for the liquid in the bottle we have that

750 ml * 1.006 g / ml = Mass [ the "ml" cancels ]

750 * 1.006 g =

754.5 g ... this is the mass ["weight "] of the liquid ...

And the acetic acid is 4% of this

So ... the mass ["weight"] of the acetic acid is 4% of this ... so

.04 * 754.5 =

30.18 g