Input interpretation
sodium amide | molar mass
Result
Find the molar mass, M, for sodium amide: 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: NaNH_2 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i H (hydrogen) | 2 N (nitrogen) | 1 Na (sodium) | 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) H (hydrogen) | 2 | 1.008 N (nitrogen) | 1 | 14.007 Na (sodium) | 1 | 22.98976928 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) H (hydrogen) | 2 | 1.008 | 2 × 1.008 = 2.016 N (nitrogen) | 1 | 14.007 | 1 × 14.007 = 14.007 Na (sodium) | 1 | 22.98976928 | 1 × 22.98976928 = 22.98976928 M = 2.016 g/mol + 14.007 g/mol + 22.98976928 g/mol = 39.013 g/mol
Unit conversion
0.039013 kg/mol (kilograms per mole)
Comparisons
≈ ( 0.054 ≈ 1/18 ) × molar mass of fullerene ( ≈ 721 g/mol )
≈ ( 0.2 ≈ 1/5 ) × molar mass of caffeine ( ≈ 194 g/mol )
≈ 0.67 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 6.5×10^-23 grams | 6.5×10^-26 kg (kilograms) | 39 u (unified atomic mass units) | 39 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 39