Input interpretation
samarium(II) iodide | molar mass
Result
Find the molar mass, M, for samarium(II) iodide: 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: SmI_2 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i I (iodine) | 2 Sm (samarium) | 1 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) | 2 | 126.90447 Sm (samarium) | 1 | 150.36 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) | 2 | 126.90447 | 2 × 126.90447 = 253.80894 Sm (samarium) | 1 | 150.36 | 1 × 150.36 = 150.36 M = 253.80894 g/mol + 150.36 g/mol = 404.17 g/mol
Unit conversion
0.40417 kg/mol (kilograms per mole)
Comparisons
≈ 0.56 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 2.1 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 6.9 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 6.7×10^-22 grams | 6.7×10^-25 kg (kilograms) | 404 u (unified atomic mass units) | 404 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 404