Input interpretation
cobaltous nitrate hexahydrate | molar mass
Result
Find the molar mass, M, for cobaltous nitrate hexahydrate: 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: Co(NO_3)_2·6H_2O Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Co (cobalt) | 1 H (hydrogen) | 12 N (nitrogen) | 2 O (oxygen) | 12 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) Co (cobalt) | 1 | 58.933194 H (hydrogen) | 12 | 1.008 N (nitrogen) | 2 | 14.007 O (oxygen) | 12 | 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) Co (cobalt) | 1 | 58.933194 | 1 × 58.933194 = 58.933194 H (hydrogen) | 12 | 1.008 | 12 × 1.008 = 12.096 N (nitrogen) | 2 | 14.007 | 2 × 14.007 = 28.014 O (oxygen) | 12 | 15.999 | 12 × 15.999 = 191.988 M = 58.933194 g/mol + 12.096 g/mol + 28.014 g/mol + 191.988 g/mol = 291.031 g/mol
Unit conversion
0.29103 kg/mol (kilograms per mole)
Comparisons
≈ 0.4 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 1.5 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 5 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 4.8×10^-22 grams | 4.8×10^-25 kg (kilograms) | 291 u (unified atomic mass units) | 291 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 291