A solution is prepared by dissolving 10.8 g ammonium sulfate in enough water to make 100.0 mL of stock solution. A 10.00 - mL sample of this stock solution is added to 50.00 mL of water. Calculate the concentration of ammonium.

Concentration ammonium is 0.036 g/mL

Explanation:

Stock solution has concentration of 0.108g/mL. Take 10mL stock solution and add 50 mL of water meaning it has 1,08g/60mL. Ammonium sulfate has 2 molecules of cation ammonium cation. So, (1,08g/60mL.) * 2=0.036 g/mL