Input interpretation
sodium nitrite | molar mass
Result
Find the molar mass, M, for sodium nitrite: 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: NaNO_2 Use the chemical formula to count the number of atoms, N_i, for each element: | number of atoms N (nitrogen) | 1 Na (sodium) | 1 O (oxygen) | 2 Look up the atomic mass, m_i, in g·mol^(-1) for each element in the periodic table: | number of atoms | atomic mass/g·mol^(-1) N (nitrogen) | 1 | 14.007 Na (sodium) | 1 | 22.98976928 O (oxygen) | 2 | 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: | | | number of atoms | atomic mass/g·mol^(-1) | mass/g·mol^(-1) N (nitrogen) | 1 | 14.007 | 1 × 14.007 = 14.007 Na (sodium) | 1 | 22.98976928 | 1 × 22.98976928 = 22.98976928 O (oxygen) | 2 | 15.999 | 2 × 15.999 = 31.998 M = 14.007 g/mol + 22.98976928 g/mol + 31.998 g/mol = 68.995 g/mol
Unit conversion
0.068995 kg/mol (kilograms per mole)
Comparisons
≈ ( 0.096 ≈ 1/10 ) × molar mass of fullerene (≈ 721 g/mol )
≈ 0.36 × molar mass of caffeine (≈ 194 g/mol )
≈ 1.2 × molar mass of sodium chloride (≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 1.1×10^-22 grams | 1.1×10^-25 kg (kilograms) | 69 u (unified atomic mass units) | 69 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 69