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

Density  =  Mass / Volume         which means that  

Volume * Density  =  Mass

Sofor 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

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

.04 * 754.5  =

30.18 g

Explanation:

Molarity =3.018 M

Explanation:

Density  =  Mass / Volume

which means that

Volume x Density  =  Mass

Sofor 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