Input interpretation
praseodymium oxide | molar mass
Result
Find the molar mass, M, for praseodymium 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: Pr_6O_11 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i O (oxygen) | 11 Pr (praseodymium) | 6 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) | 11 | 15.999 Pr (praseodymium) | 6 | 140.90766 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) | 11 | 15.999 | 11 × 15.999 = 175.989 Pr (praseodymium) | 6 | 140.90766 | 6 × 140.90766 = 845.44596 M = 175.989 g/mol + 845.44596 g/mol = 1021.435 g/mol
Unit conversion
1.02143 kg/mol (kilograms per mole)
Comparisons
≈ 1.4 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 5.3 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 17 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 1.7×10^-21 grams | 1.7×10^-24 kg (kilograms) | 1021 u (unified atomic mass units) | 1 kDa (kilodalton)
Relative molecular mass M_r from M_r = M_u/M: | 1021