Input interpretation
![cupric bromide | molar mass](../image_source/b8f81e0cf1183812642ca6ea349bd1d1.png)
cupric bromide | molar mass
Result
![Find the molar mass, M, for cupric bromide: 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: CuBr_2 Use the chemical formula, CuBr_2, to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 2 Cu (copper) | 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) Br (bromine) | 2 | 79.904 Cu (copper) | 1 | 63.546 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) | 2 | 79.904 | 2 × 79.904 = 159.808 Cu (copper) | 1 | 63.546 | 1 × 63.546 = 63.546 M = 159.808 g/mol + 63.546 g/mol = 223.354 g/mol](../image_source/9a7a2f0f6198e78da722b6657bbea45e.png)
Find the molar mass, M, for cupric bromide: 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: CuBr_2 Use the chemical formula, CuBr_2, to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 2 Cu (copper) | 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) Br (bromine) | 2 | 79.904 Cu (copper) | 1 | 63.546 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) | 2 | 79.904 | 2 × 79.904 = 159.808 Cu (copper) | 1 | 63.546 | 1 × 63.546 = 63.546 M = 159.808 g/mol + 63.546 g/mol = 223.354 g/mol
Unit conversion
![0.22335 kg/mol (kilograms per mole)](../image_source/1054527fc337d684bd276c09c4e8ea52.png)
0.22335 kg/mol (kilograms per mole)
Comparisons
![≈ 0.31 × molar mass of fullerene ( ≈ 721 g/mol )](../image_source/db02e662e5e6842fee19fe05d3f8734b.png)
≈ 0.31 × molar mass of fullerene ( ≈ 721 g/mol )
![≈ 1.2 × molar mass of caffeine ( ≈ 194 g/mol )](../image_source/096ef7997f6e076736d4bedb80f461d1.png)
≈ 1.2 × molar mass of caffeine ( ≈ 194 g/mol )
![≈ 3.8 × molar mass of sodium chloride ( ≈ 58 g/mol )](../image_source/ef4e68e40df446fb4b00a69712288e88.png)
≈ 3.8 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 3.7×10^-22 grams | 3.7×10^-25 kg (kilograms) | 223 u (unified atomic mass units) | 223 Da (daltons)](../image_source/7de071387c26784613b990bfb9537ad3.png)
Mass of a molecule m from m = M/N_A: | 3.7×10^-22 grams | 3.7×10^-25 kg (kilograms) | 223 u (unified atomic mass units) | 223 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 223](../image_source/eddb13cb1aade05ed577c16697e6445a.png)
Relative molecular mass M_r from M_r = M_u/M: | 223