Input interpretation
trimethylphosphine | molar mass
Result
Find the molar mass, M, for trimethylphosphine: 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)_3P Use the chemical formula, (CH_3)_3P, to count the number of atoms, N_i, for each element: | N_i C (carbon) | 3 H (hydrogen) | 9 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) C (carbon) | 3 | 12.011 H (hydrogen) | 9 | 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) C (carbon) | 3 | 12.011 | 3 × 12.011 = 36.033 H (hydrogen) | 9 | 1.008 | 9 × 1.008 = 9.072 P (phosphorus) | 1 | 30.973761998 | 1 × 30.973761998 = 30.973761998 M = 36.033 g/mol + 9.072 g/mol + 30.973761998 g/mol = 76.079 g/mol
Unit conversion
0.07608 kg/mol (kilograms per mole)
Comparisons
≈ ( 0.11 ≈ 1/10 ) × molar mass of fullerene ( ≈ 721 g/mol )
≈ 0.39 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 1.3 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 1.3×10^-22 grams | 1.3×10^-25 kg (kilograms) | 76 u (unified atomic mass units) | 76 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 76