Input interpretation
boron trifluoride | molecular mass
Result
Find the molecular mass, m, for boron trifluoride: 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: BF_3 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i B (boron) | 1 F (fluorine) | 3 Look up the atomic mass, m_i, in unified atomic mass units, u, for each element in the periodic table: | N_i | m_i/u B (boron) | 1 | 10.81 F (fluorine) | 3 | 18.998403163 Multiply N_i by m_i to compute the mass for each element. Then sum those values to compute the molecular mass, m: Answer: | | | N_i | m_i/u | mass/u B (boron) | 1 | 10.81 | 1 × 10.81 = 10.81 F (fluorine) | 3 | 18.998403163 | 3 × 18.998403163 = 56.995209489 m = 10.81 u + 56.995209489 u = 67.81 u
Unit conversions
67.81 Da (daltons)
0.06781 kDa (kilodaltons)
1.1259×10^-22 grams
1.1259×10^-25 kg (kilograms)
67.81 chemical atomic mass units (unit officially deprecated)
67.83 physical atomic mass units (unit officially deprecated)
Comparisons as mass of molecule
≈ ( 0.094 ≈ 1/11 ) × molecular mass of fullerene ( ≈ 721 u )
≈ 0.35 × molecular mass of caffeine ( ≈ 194 u )
≈ 1.2 × molecular mass of sodium chloride ( ≈ 58 u )
Corresponding quantities
Relative atomic mass A_r from A_r = m_aN_A/M_u: | 68
Molar mass M from M = m_aN_A: | 68 g/mol (grams per mole)
Relative molecular mass M_r from M_r = m_mN_A/M_u: | 68
Molar mass M from M = m_mN_A: | 68 g/mol (grams per mole)