Input interpretation
etioporphyrin idihydrobromide | molar mass
Result
Find the molar mass, M, for etioporphyrin idihydrobromide: 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: C_32H_38N_4·2HBr Use the chemical formula, C_32H_38N_4·2HBr, to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 2 C (carbon) | 32 H (hydrogen) | 40 N (nitrogen) | 4 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) Br (bromine) | 2 | 79.904 C (carbon) | 32 | 12.011 H (hydrogen) | 40 | 1.008 N (nitrogen) | 4 | 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) Br (bromine) | 2 | 79.904 | 2 × 79.904 = 159.808 C (carbon) | 32 | 12.011 | 32 × 12.011 = 384.352 H (hydrogen) | 40 | 1.008 | 40 × 1.008 = 40.320 N (nitrogen) | 4 | 14.007 | 4 × 14.007 = 56.028 M = 159.808 g/mol + 384.352 g/mol + 40.320 g/mol + 56.028 g/mol = 640.508 g/mol
Unit conversion
0.6405 kg/mol (kilograms per mole)
Comparisons
≈ 0.89 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 3.3 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 11 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 1.1×10^-21 grams | 1.1×10^-24 kg (kilograms) | 641 u (unified atomic mass units) | 641 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 641