1. The problem statement, all variables and given/known data An aqueous solution containing SO42- and PO43- is provided. Using this solution,dil.HNO3 and dil NaOH only,outline a method to determine the concentration of SO42- and PO43- in the sample 2. Relevant equations n/a 3. The attempt at a solution Well,I'm not really sure how to do this 'cos i'm not very sure of the reactions.Anyway this is what I think, first, find the initial volume of the solution.next we have to find the no. of moles of each ion present, to find the concentration. To find the no. of moles, we add excess dilute NaOH to the sample,then we get 2 colourless solutions of Na2SO4 and Na3PO4. To this solution we then add,dil nitric acid,Im thinking one would give a gas and one wouldn't.The one that gives out a gas contains sulphate ions, 3Na2SO4 + 6HNO3[tex]\rightarrow[/tex]3SO2+6NaNO3+3H2O Is the above equation correct?I know that a sulphite gives SO2 with an acid but does a sulphate also give the same products?