Input interpretation
magnesium perchlorate | molar mass
Result
Find the molar mass, M, for magnesium perchlorate: 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: Mg(ClO_4)_2 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Cl (chlorine) | 2 Mg (magnesium) | 1 O (oxygen) | 8 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) Cl (chlorine) | 2 | 35.45 Mg (magnesium) | 1 | 24.305 O (oxygen) | 8 | 15.999 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) Cl (chlorine) | 2 | 35.45 | 2 × 35.45 = 70.90 Mg (magnesium) | 1 | 24.305 | 1 × 24.305 = 24.305 O (oxygen) | 8 | 15.999 | 8 × 15.999 = 127.992 M = 70.90 g/mol + 24.305 g/mol + 127.992 g/mol = 223.20 g/mol
Unit conversion
0.2232 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) | 223 u (unified atomic mass units) | 223 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 223