Input interpretation
![gallium(III) bromide | molar mass](../image_source/9f3a598ccfaba1f71eac745aa48c522b.png)
gallium(III) bromide | molar mass
Result
![Find the molar mass, M, for gallium(III) 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: GaBr_3 Use the chemical formula, GaBr_3, to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 3 Ga (gallium) | 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) | 3 | 79.904 Ga (gallium) | 1 | 69.723 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) | 3 | 79.904 | 3 × 79.904 = 239.712 Ga (gallium) | 1 | 69.723 | 1 × 69.723 = 69.723 M = 239.712 g/mol + 69.723 g/mol = 309.435 g/mol](../image_source/6feee0c6700f5a0990a33bf0afd24125.png)
Find the molar mass, M, for gallium(III) 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: GaBr_3 Use the chemical formula, GaBr_3, to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 3 Ga (gallium) | 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) | 3 | 79.904 Ga (gallium) | 1 | 69.723 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) | 3 | 79.904 | 3 × 79.904 = 239.712 Ga (gallium) | 1 | 69.723 | 1 × 69.723 = 69.723 M = 239.712 g/mol + 69.723 g/mol = 309.435 g/mol
Unit conversion
![0.30943 kg/mol (kilograms per mole)](../image_source/91df8069dd690562efc35b6a35a2b2a0.png)
0.30943 kg/mol (kilograms per mole)
Comparisons
![≈ 0.43 × molar mass of fullerene ( ≈ 721 g/mol )](../image_source/a60697b7ef88cf99822d84924ac0709e.png)
≈ 0.43 × molar mass of fullerene ( ≈ 721 g/mol )
![≈ 1.6 × molar mass of caffeine ( ≈ 194 g/mol )](../image_source/443d750c97c35c36d7c9764b669b2a14.png)
≈ 1.6 × molar mass of caffeine ( ≈ 194 g/mol )
![≈ 5.3 × molar mass of sodium chloride ( ≈ 58 g/mol )](../image_source/57e61a1bd267b1fd79217a3291eaed9b.png)
≈ 5.3 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 5.1×10^-22 grams | 5.1×10^-25 kg (kilograms) | 309 u (unified atomic mass units) | 309 Da (daltons)](../image_source/23e370b7c80782684796c0296764dd96.png)
Mass of a molecule m from m = M/N_A: | 5.1×10^-22 grams | 5.1×10^-25 kg (kilograms) | 309 u (unified atomic mass units) | 309 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 309](../image_source/f4993fc7c2dba8443298140555d8c765.png)
Relative molecular mass M_r from M_r = M_u/M: | 309