text: To determine the mass percent of Ca in Ca(CN)2 all you have to do is find the mass of Ca, divide it by the total mass of Ca(CN)2, then multiply by 100.  \n\nTherefore:\n\nmass of Ca = 40.08 amu (or g/mol)\nmass of Ca(CN)2 = 92.10 amu (or g/mol)\n\n(40.08 amu / 92.10 amu) x 100 = 43.52% Ca in Ca(CN)2