A sample of a substance known to contain chloride ions was dissolved in distilled water in a 1L volumetric flask. Then 25.00 mL of this solution was treated with excess silver nitrate, AgNO3 (aq). The precipitate of silver chloride, AgCl (s) was filtered and dried. The mass of the dry precipitate was 0.765 g.
a. Calculate the concentration of chloride ions.
b. If the original substance was sodium chloride, NaCl (s), what mass of it was dissolved in the volumetric flask?
This is incorrect. Part A requires you to use 0.025L for the volume in
the formula c=n/v. You used 1L. Also, part B is incorrect. You needed
to use the concentration of chloride ion from part A which was
0.214mol/L and get the moles of NaCl by dividing 1L to get 0.214 moles
of NaCl. Then you can multiply this with the molar mass of NaCl. So
your answer would be 12.5grams
Leave a comment
Thank you! Your comments have been successfully added. However, they need to be checked by the moderator before being published.