Input interpretation
osmium(IV) oxide | molar mass
Result
Find the molar mass, M, for osmium(IV) oxide: 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: OsO_2 Use the chemical formula, OsO_2, to count the number of atoms, N_i, for each element: | N_i O (oxygen) | 2 Os (osmium) | 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) O (oxygen) | 2 | 15.999 Os (osmium) | 1 | 190.23 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) O (oxygen) | 2 | 15.999 | 2 × 15.999 = 31.998 Os (osmium) | 1 | 190.23 | 1 × 190.23 = 190.23 M = 31.998 g/mol + 190.23 g/mol = 222.23 g/mol
Unit conversion
0.22223 kg/mol (kilograms per mole)
Comparisons
≈ 0.31 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 1.1 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 3.8 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 3.7×10^-22 grams | 3.7×10^-25 kg (kilograms) | 222 u (unified atomic mass units) | 222 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 222