Units

         I.   Units used in Water Quality Analysis -  w/v    

                mg/L     or    parts per million (ppm)   same as mg/ml

                      mg/L     or    parts per billion (ppb)   same as ng/ml

                 Molar (M)    or    moles/liter  - usually too small a number

                 mmol/L    =   moles/L x 10⁶ mmole/mole

            Normal    =  Equivalent per liter (eq/L)  -  usually too small a number
                                       an equivalent of A reacts with an equivalent of B
                                       since this is often a function of charge,
                                       an equivalent is usually a mole of charge

                 meq/L      =   eq/L x 10⁶ meq/Eq  

        II.  Converting Units -  multiply by factors of one

              A.  Convert mg/L to mmol/L for Na⁺ (atomic wt. = 23)

Explanation

              B.  Convert mmol/L to meq/L for SO₄^2- (molecular wt. = 32+4x16 = 96)

Explanation

              C.  Convert mg/L to mg/L   (ppm to ppb)

Explanation