Volume content question
I have a stoichiometry exam tomorrow and I wondered exactly what volume content is, it is not explained in my chem book. How does it differ from mass content, like the mass content for H2 in water is (M(H2)/M(H2O))*100, is it the same for volume content but with volume instead? Like the volume content for NaCl dissolving in water V(NaCl)/V(NaCl+H20)?