molar mass of stearyltributylphosphonium bromide

stearyltributylphosphonium bromide | molar mass

Find the molar mass, M, for stearyltributylphosphonium bromide: 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: CH_3(CH_2)_17P[(CH_2)_3CH_3]_3Br Use the chemical formula, CH_3(CH_2)_17P[(CH_2)_3CH_3]_3Br, to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 1 C (carbon) | 30 H (hydrogen) | 64 P (phosphorus) | 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) Br (bromine) | 1 | 79.904 C (carbon) | 30 | 12.011 H (hydrogen) | 64 | 1.008 P (phosphorus) | 1 | 30.973761998 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) | 1 | 79.904 | 1 × 79.904 = 79.904 C (carbon) | 30 | 12.011 | 30 × 12.011 = 360.330 H (hydrogen) | 64 | 1.008 | 64 × 1.008 = 64.512 P (phosphorus) | 1 | 30.973761998 | 1 × 30.973761998 = 30.973761998 M = 79.904 g/mol + 360.330 g/mol + 64.512 g/mol + 30.973761998 g/mol = 535.720 g/mol

0.5357 kg/mol (kilograms per mole)

≈ 0.74 × molar mass of fullerene ( ≈ 721 g/mol )

≈ 2.8 × molar mass of caffeine ( ≈ 194 g/mol )

≈ 9.2 × molar mass of sodium chloride ( ≈ 58 g/mol )

Mass of a molecule m from m = M/N_A: | 8.9×10^-22 grams | 8.9×10^-25 kg (kilograms) | 536 u (unified atomic mass units) | 536 Da (daltons)

Relative molecular mass M_r from M_r = M_u/M: | 536