Input interpretation
triphenylborane | molar mass
Result
Find the molar mass, M, for triphenylborane: 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_6H_5)_3B Use the chemical formula to count the number of atoms, N_i, for each element: | N_i B (boron) | 1 C (carbon) | 18 H (hydrogen) | 15 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) B (boron) | 1 | 10.81 C (carbon) | 18 | 12.011 H (hydrogen) | 15 | 1.008 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) B (boron) | 1 | 10.81 | 1 × 10.81 = 10.81 C (carbon) | 18 | 12.011 | 18 × 12.011 = 216.198 H (hydrogen) | 15 | 1.008 | 15 × 1.008 = 15.120 M = 10.81 g/mol + 216.198 g/mol + 15.120 g/mol = 242.13 g/mol
Unit conversion
0.24213 kg/mol (kilograms per mole)
Comparisons
≈ 0.34 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 1.2 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 4.1 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 4×10^-22 grams | 4×10^-25 kg (kilograms) | 242 u (unified atomic mass units) | 242 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 242