= AgCl2

AgCl2 (chemical compound)

molar mass | 178.8 g/mol formula | AgCl2 empirical formula | Ag_Cl_2

Find the elemental composition for AgCl2 in terms of the atom and mass percents: atom percent = N_i/N_atoms × 100% mass percent = (N_im_i)/m × 100% Plan: • Write the chemical formula and gather atomic masses from the periodic table. • Determine values for N_i, m_i, N_atoms and m using these items. • Finally, compute the percents and check the results. Use the chemical formula to count the number of atoms, N_i, for each element and find the total number of atoms, N_atoms, per molecule: | number of atoms Ag (silver) | 1 Cl (chlorine) | 2 N_atoms = 1 + 2 = 3 Divide each N_i by N_atoms to calculate atom fractions. Then use the property that atom fractions must sum to one to check the work: | number of atoms | atom fraction Ag (silver) | 1 | 1/3 Cl (chlorine) | 2 | 2/3 Check: 1/3 + 2/3 = 1 Compute atom percents using the atom fractions: | number of atoms | atom percent Ag (silver) | 1 | 1/3 × 100% = 33.3% Cl (chlorine) | 2 | 2/3 × 100% = 66.7% Look up the atomic mass, m_i, in unified atomic mass units, u, for each element in the periodic table: | number of atoms | atom percent | atomic mass/u Ag (silver) | 1 | 33.3% | 107.8682 Cl (chlorine) | 2 | 66.7% | 35.45 Multiply N_i by m_i to compute the mass for each element. Then sum those values to compute the molecular mass, m: | number of atoms | atom percent | atomic mass/u | mass/u Ag (silver) | 1 | 33.3% | 107.8682 | 1 × 107.8682 = 107.8682 Cl (chlorine) | 2 | 66.7% | 35.45 | 2 × 35.45 = 70.90 m = 107.8682 u + 70.90 u = 178.7682 u Divide the mass for each element by m to calculate mass fractions. Then use the property that mass fractions must sum to one to check the work: | number of atoms | atom percent | mass fraction Ag (silver) | 1 | 33.3% | 107.8682/178.7682 Cl (chlorine) | 2 | 66.7% | 70.90/178.7682 Check: 107.8682/178.7682 + 70.90/178.7682 = 1 Compute mass percents using the mass fractions: Answer: | | | number of atoms | atom percent | mass percent Ag (silver) | 1 | 33.3% | 107.8682/178.7682 × 100% = 60.34% Cl (chlorine) | 2 | 66.7% | 70.90/178.7682 × 100% = 39.66%

Mass fraction pie chart