Input interpretation
(2-ethylhexyl)magnesium bromide | molar mass
Result
Find the molar mass, M, for (2-ethylhexyl)magnesium 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: C_8H_17BrMg Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 1 C (carbon) | 8 H (hydrogen) | 17 Mg (magnesium) | 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) | 1 | 79.904 C (carbon) | 8 | 12.011 H (hydrogen) | 17 | 1.008 Mg (magnesium) | 1 | 24.305 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 C (carbon) | 8 | 12.011 | 8 × 12.011 = 96.088 H (hydrogen) | 17 | 1.008 | 17 × 1.008 = 17.136 Mg (magnesium) | 1 | 24.305 | 1 × 24.305 = 24.305 M = 79.904 g/mol + 96.088 g/mol + 17.136 g/mol + 24.305 g/mol = 217.433 g/mol
Unit conversion
0.21743 kg/mol (kilograms per mole)
Comparisons
≈ 0.3 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 1.1 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 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) | 217 u (unified atomic mass units) | 217 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 217