Input interpretation
mercuric cyanide | molar mass
Result
Find the molar mass, M, for mercuric cyanide: 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: Hg(CN)_2 Use the chemical formula, Hg(CN)_2, to count the number of atoms, N_i, for each element: | N_i C (carbon) | 2 Hg (mercury) | 1 N (nitrogen) | 2 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) C (carbon) | 2 | 12.011 Hg (mercury) | 1 | 200.592 N (nitrogen) | 2 | 14.007 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) C (carbon) | 2 | 12.011 | 2 × 12.011 = 24.022 Hg (mercury) | 1 | 200.592 | 1 × 200.592 = 200.592 N (nitrogen) | 2 | 14.007 | 2 × 14.007 = 28.014 M = 24.022 g/mol + 200.592 g/mol + 28.014 g/mol = 252.628 g/mol
Unit conversion
0.252628 kg/mol (kilograms per mole)
Comparisons
≈ 0.35 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 1.3 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 4.3 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 4.2×10^-22 grams | 4.2×10^-25 kg (kilograms) | 253 u (unified atomic mass units) | 253 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 253