What is the percentage by mass of CL in PtCl2(NH3)2?
This question can be done simply by using the molar mass of cl2 divided by the total molar mass
so , there are two cl2, so the molar mass is 35.5 x 2 = 71 for the cl
71 / (195+71+28+6) = 23.7%
Source(s): Me, chem college student