Input interpretation
2, 5-dibromo-3-dodecylthiophene | molar mass
Result
Find the molar mass, M, for 2, 5-dibromo-3-dodecylthiophene: 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_16H_26Br_2S Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 2 C (carbon) | 16 H (hydrogen) | 26 S (sulfur) | 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) | 16 | 12.011 H (hydrogen) | 26 | 1.008 S (sulfur) | 1 | 32.06 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) | 16 | 12.011 | 16 × 12.011 = 192.176 H (hydrogen) | 26 | 1.008 | 26 × 1.008 = 26.208 S (sulfur) | 1 | 32.06 | 1 × 32.06 = 32.06 M = 159.808 g/mol + 192.176 g/mol + 26.208 g/mol + 32.06 g/mol = 410.25 g/mol
Unit conversion
0.41025 kg/mol (kilograms per mole)
Comparisons
≈ 0.57 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 2.1 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 7 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 6.8×10^-22 grams | 6.8×10^-25 kg (kilograms) | 410 u (unified atomic mass units) | 410 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 410