Input interpretation
ethanone, 2-bromo-1, 2-diphenyl- | molar mass
Result
Find the molar mass, M, for ethanone, 2-bromo-1, 2-diphenyl-: 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_6H_5CH(Br)COC_6H_5 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 1 C (carbon) | 14 H (hydrogen) | 11 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) | 1 | 79.904 C (carbon) | 14 | 12.011 H (hydrogen) | 11 | 1.008 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) | 1 | 79.904 | 1 × 79.904 = 79.904 C (carbon) | 14 | 12.011 | 14 × 12.011 = 168.154 H (hydrogen) | 11 | 1.008 | 11 × 1.008 = 11.088 O (oxygen) | 1 | 15.999 | 1 × 15.999 = 15.999 M = 79.904 g/mol + 168.154 g/mol + 11.088 g/mol + 15.999 g/mol = 275.145 g/mol
Unit conversion
0.27514 kg/mol (kilograms per mole)
Comparisons
≈ 0.38 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 1.4 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 4.7 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 4.6×10^-22 grams | 4.6×10^-25 kg (kilograms) | 275 u (unified atomic mass units) | 275 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 275