You have a solution that contains ni 2 and pb 2 ions. you wish to use selective precipitation to separate the ions. you have available at your lab 0.500 m solutions of na2co3 and naoh. which solution should you add to your solution to achieve the best separation of nickel(ii) and lead(ii) ions

We need to assume that the acid in question is a liquid (not a solid or a gas),

and we need to assume that the 16.1% is specified as 16.1% (v/v) ,

where "v/v" means volume in volume,

meaning 16.2 milliliters of that acid are contained in 100 milliliters of the solution of acid and water.

With those assumptions, the ratio of acid volume to solution volume is

x/342 = 16.1/100 , where x= number of milliliters of acid in the 342

milliliters of solution.

x/342 = 16./100 ---> x=342x16.1/100 ---> x=55 (Rounded)