Input interpretation
1, 2-dibromo-1, 1, 2-trichloroethane | molar mass
Result
Find the molar mass, M, for 1, 2-dibromo-1, 1, 2-trichloroethane: 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: Cl_2C(Br)CH(Cl)Br Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 2 C (carbon) | 2 Cl (chlorine) | 3 H (hydrogen) | 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) | 2 | 12.011 Cl (chlorine) | 3 | 35.45 H (hydrogen) | 1 | 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) | 2 | 12.011 | 2 × 12.011 = 24.022 Cl (chlorine) | 3 | 35.45 | 3 × 35.45 = 106.35 H (hydrogen) | 1 | 1.008 | 1 × 1.008 = 1.008 M = 159.808 g/mol + 24.022 g/mol + 106.35 g/mol + 1.008 g/mol = 291.19 g/mol
Unit conversion
0.2912 kg/mol (kilograms per mole)
Comparisons
≈ 0.4 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 1.5 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 5 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 4.8×10^-22 grams | 4.8×10^-25 kg (kilograms) | 291 u (unified atomic mass units) | 291 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 291