Input interpretation
potassium fluoride | molecular mass
Result
Find the molecular mass, m, for potassium fluoride: 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: KF Use the chemical formula, KF, to count the number of atoms, N_i, for each element: | N_i F (fluorine) | 1 K (potassium) | 1 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 F (fluorine) | 1 | 18.998403163 K (potassium) | 1 | 39.0983 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 F (fluorine) | 1 | 18.998403163 | 1 × 18.998403163 = 18.998403163 K (potassium) | 1 | 39.0983 | 1 × 39.0983 = 39.0983 m = 18.998403163 u + 39.0983 u = 58.0967 u
Unit conversions
58.0967 Da (daltons)
0.0580967 kDa (kilodaltons)
9.64718×10^-23 grams
9.64718×10^-26 kg (kilograms)
58.0992 chemical atomic mass units (unit officially deprecated)
58.1152 physical atomic mass units (unit officially deprecated)
Comparisons as mass of molecule
≈ ( 0.081 ≈ 1/12 ) × molecular mass of fullerene ( ≈ 721 u )
≈ 0.3 × molecular mass of caffeine ( ≈ 194 u )
≈ 0.994 × molecular mass of sodium chloride ( 58.443 u )
Corresponding quantities
Relative atomic mass A_r from A_r = m_aN_A/M_u: | 58
Molar mass M from M = m_aN_A: | 58 g/mol (grams per mole)
Relative molecular mass M_r from M_r = m_mN_A/M_u: | 58
Molar mass M from M = m_mN_A: | 58 g/mol (grams per mole)