Question: how many moles are in 10 ml of vinegar?
Answer: The density of acetic acid is 1.05 g/cc at ambient temperature, and the molar mass is 60.05 g/mol. Therefore in 20 ml of vinegar, you will have (1 x 1.05/60.05) = 0.0175 moles of acetic acid. But you cannot quote "moles of vinegar" because vinegar isn't a compound, its a mixture.