Input interpretation
sodium hydride | molar mass
Result
Find the molar mass, M, for sodium hydride: 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: NaH Use the chemical formula to count the number of atoms, N_i, for each element: | N_i H (hydrogen) | 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) | 1 | 1.008 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) | 1 | 1.008 | 1 × 1.008 = 1.008 Na (sodium) | 1 | 22.98976928 | 1 × 22.98976928 = 22.98976928 M = 1.008 g/mol + 22.98976928 g/mol = 23.998 g/mol
Unit conversion
0.023998 kg/mol (kilograms per mole)
Comparisons
≈ ( 0.12 ≈ 1/8 ) × molar mass of caffeine ( ≈ 194 g/mol )
≈ 0.41 × molar mass of sodium chloride ( ≈ 58 g/mol )
≈ 1.3 × molar mass of water ( ≈ 18 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 4×10^-23 grams | 4×10^-26 kg (kilograms) | 24 u (unified atomic mass units) | 24 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 24