That compound is beryllium oxalate. Beryllium, an alkaline earth metal, has two valence electrons, which it will lose to the oxalate polyatomic ion.
BeC2O4 = 97.0 g/1 mol BeC2O4-3H2O = 151.0 g/1 mol 3.21 g BeC2O4-3H2O * 1 mol/151.0 g = 0.021258 mol BeC2O4-3H2O 0.021258 mol BeC2O4-3H2O * 97.0 g/1 mol = 2.06 g BeC2O4
To calculate the mass percent of carbon in BeC2O4 x 3H2O, we need to find the molar mass of carbon in the compound and divide it by the molar mass of the entire compound, then multiply by 100. The molar mass of carbon in BeC2O4 is 12 g/mol, and the molar mass of BeC2O4 x 3H2O is 151 g/mol. Therefore, the mass percent of carbon in BeC2O4 x 3H2O is (12/151) x 100 = 7.9%.