Input interpretation
bromine pentafluoride | molar mass
Result
Find the molar mass, M, for bromine pentafluoride: 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: BrF_5 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 1 F (fluorine) | 5 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 F (fluorine) | 5 | 18.998403163 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 F (fluorine) | 5 | 18.998403163 | 5 × 18.998403163 = 94.992015815 M = 79.904 g/mol + 94.992015815 g/mol = 174.896 g/mol
Unit conversion
0.1749 kg/mol (kilograms per mole)
Comparisons
≈ ( 0.24 ≈ 1/4 ) × molar mass of fullerene ( ≈ 721 g/mol )
≈ 0.9 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 3 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 2.9×10^-22 grams | 2.9×10^-25 kg (kilograms) | 175 u (unified atomic mass units) | 175 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 175