Input interpretation
![manganese(II) bromide | molar mass](../image_source/38b86101f8ff54f1eb3544f327acb6f8.png)
manganese(II) bromide | molar mass
Result
![Find the molar mass, M, for manganese(II) 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: MnBr_2 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 2 Mn (manganese) | 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 Mn (manganese) | 1 | 54.938044 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 Mn (manganese) | 1 | 54.938044 | 1 × 54.938044 = 54.938044 M = 159.808 g/mol + 54.938044 g/mol = 214.746 g/mol](../image_source/0347dcfa1fef11806bdf0af96df93e50.png)
Find the molar mass, M, for manganese(II) 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: MnBr_2 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 2 Mn (manganese) | 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 Mn (manganese) | 1 | 54.938044 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 Mn (manganese) | 1 | 54.938044 | 1 × 54.938044 = 54.938044 M = 159.808 g/mol + 54.938044 g/mol = 214.746 g/mol
Unit conversion
![0.21475 kg/mol (kilograms per mole)](../image_source/c8e104d266fe0d64f61da2adf732369f.png)
0.21475 kg/mol (kilograms per mole)
Comparisons
![≈ 0.3 × molar mass of fullerene ( ≈ 721 g/mol )](../image_source/ade8aeaa002b9bf4195f2cd90db3a2f3.png)
≈ 0.3 × molar mass of fullerene ( ≈ 721 g/mol )
![≈ 1.1 × molar mass of caffeine ( ≈ 194 g/mol )](../image_source/8d45bc3f9d2e183d3519acd9ba9363a1.png)
≈ 1.1 × molar mass of caffeine ( ≈ 194 g/mol )
![≈ 3.7 × molar mass of sodium chloride ( ≈ 58 g/mol )](../image_source/192d7b1bea320b583d6e62be0bd9df52.png)
≈ 3.7 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 3.6×10^-22 grams | 3.6×10^-25 kg (kilograms) | 215 u (unified atomic mass units) | 215 Da (daltons)](../image_source/b67ad76cb27c6e21dca873c553adeba0.png)
Mass of a molecule m from m = M/N_A: | 3.6×10^-22 grams | 3.6×10^-25 kg (kilograms) | 215 u (unified atomic mass units) | 215 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 215](../image_source/af57713ce3fec41797e7afd3377a899b.png)
Relative molecular mass M_r from M_r = M_u/M: | 215