There are various forms of the concentration expression,
"mass of stuff"/"volume of solution"mass of stuffvolume of solution, "mass of stuff"/"mass of solution"mass of stuffmass of solution. Most commonly used is "molarity"="moles of stuff"/"volume of solution"molarity=moles of stuffvolume of solution...and units of mol*L^-1mol⋅L−1 result. Weaker concentrations CAN be quoted in terms of "parts per million"parts per million..."1 ppm"-=1*mg*L^-1("of AQUEOUS solution")1 ppm≡1⋅mg⋅L−1(of AQUEOUS solution)..
The product, "volume (L)"xxmol*L^-1volume (L)×mol⋅L−1 gives an answer in molmol..
Unless, you are given the composition of the solution, i.e. 10*g10⋅g of HClHCl is dissolved in enuff water to give 1*L1⋅L of solution, you are usually quoted solution concentration. In these circumstances we would take....
((10*g)/(36.46*g*mol^-1))/(1*L)=0.274*mol*L^-110⋅g36.46⋅g⋅mol−11⋅L=0.274⋅mol⋅L−1...WITH RESPECT to HClHCl...of course the acid speciates in solution..to give [H_3O^+]=[Cl^-]=0.274*mol*L^-1[H3O+]=[Cl−]=0.274⋅mol⋅L−1..
