Input interpretation
magnesium bromide ethyl etherate | molar mass
Result
Find the molar mass, M, for magnesium bromide ethyl etherate: 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: MgBr_2·O(C_2H_5)_2 Use the chemical formula, MgBr_2·O(C_2H_5)_2, to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 2 C (carbon) | 4 H (hydrogen) | 10 Mg (magnesium) | 1 O (oxygen) | 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 C (carbon) | 4 | 12.011 H (hydrogen) | 10 | 1.008 Mg (magnesium) | 1 | 24.305 O (oxygen) | 1 | 15.999 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 C (carbon) | 4 | 12.011 | 4 × 12.011 = 48.044 H (hydrogen) | 10 | 1.008 | 10 × 1.008 = 10.080 Mg (magnesium) | 1 | 24.305 | 1 × 24.305 = 24.305 O (oxygen) | 1 | 15.999 | 1 × 15.999 = 15.999 M = 159.808 g/mol + 48.044 g/mol + 10.080 g/mol + 24.305 g/mol + 15.999 g/mol = 258.236 g/mol
Unit conversion
0.25824 kg/mol (kilograms per mole)
Comparisons
≈ 0.36 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 1.3 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 4.4 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 4.3×10^-22 grams | 4.3×10^-25 kg (kilograms) | 258 u (unified atomic mass units) | 258 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 258