Input interpretation
9, 9-didodecyl-2, 7-dibromofluorene | molar mass
Result
Find the molar mass, M, for 9, 9-didodecyl-2, 7-dibromofluorene: 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_37H_56Br_2 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 2 C (carbon) | 37 H (hydrogen) | 56 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) | 37 | 12.011 H (hydrogen) | 56 | 1.008 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) | 37 | 12.011 | 37 × 12.011 = 444.407 H (hydrogen) | 56 | 1.008 | 56 × 1.008 = 56.448 M = 159.808 g/mol + 444.407 g/mol + 56.448 g/mol = 660.663 g/mol
Unit conversion
0.6607 kg/mol (kilograms per mole)
Comparisons
≈ 0.92 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 3.4 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 11 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 1.1×10^-21 grams | 1.1×10^-24 kg (kilograms) | 661 u (unified atomic mass units) | 661 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 661