Input interpretation
diphosphorous tetraiodide | molar mass
Result
Find the molar mass, M, for diphosphorous tetraiodide: M = sum _iN_im_i Plan: • Write the chemical formula and gather atomic masses from the periodic table. • Determine values for N_i and m_i using these items. • Finally, compute the mass. Write the chemical formula: P_2I_4 Use the chemical formula, P_2I_4, to count the number of atoms, N_i, for each element: | N_i I (iodine) | 4 P (phosphorus) | 2 Look up the atomic mass, m_i, in g·mol^(-1) for each element in the periodic table: | N_i | m_i/g·mol^(-1) I (iodine) | 4 | 126.90447 P (phosphorus) | 2 | 30.973761998 Multiply N_i by m_i to compute the mass for each element. Then sum those values to compute the molar mass, M: Answer: | | | N_i | m_i/g·mol^(-1) | mass/g·mol^(-1) I (iodine) | 4 | 126.90447 | 4 × 126.90447 = 507.61788 P (phosphorus) | 2 | 30.973761998 | 2 × 30.973761998 = 61.947523996 M = 507.61788 g/mol + 61.947523996 g/mol = 569.56540 g/mol
Unit conversion
0.5695654 kg/mol (kilograms per mole)
Comparisons
≈ 0.79 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 2.9 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 9.7 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 9.5×10^-22 grams | 9.5×10^-25 kg (kilograms) | 570 u (unified atomic mass units) | 570 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 570