Using 4.869g of COCL2 and distilled water, how would you prepare 100mL of a 0.0600M solution of CoCl2?

Answer 1

Please, do not write Co as CO, or Cl as CL.
First check if 4.869g anhydrous CoCl2 is sufficient or not.
The molar mass of CoCl2 is: 129.84 g/mol
The required CoCl2 is: 0.100*0.0600*129.84 g = 0.779 g
That means 4.869g of CoCl2 can make 625 ml of 0.0600M solution of CoCl2. To avoid anhydrous CoCl2 absorb water and convert to CoCl2·6H2O during your weighing period, you may put all 4.869g of CoCl2 into a cylindrical measure, dissolve it, and add distilled water to 625ml. Finally take 100ml of the solution.