Input interpretation
bromophos-ethyl | molar mass
Result
Find the molar mass, M, for bromophos-ethyl: 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_10H_12BrCl_2O_3PS Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 1 C (carbon) | 10 Cl (chlorine) | 2 H (hydrogen) | 12 O (oxygen) | 3 P (phosphorus) | 1 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) | 1 | 79.904 C (carbon) | 10 | 12.011 Cl (chlorine) | 2 | 35.45 H (hydrogen) | 12 | 1.008 O (oxygen) | 3 | 15.999 P (phosphorus) | 1 | 30.973761998 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) | 1 | 79.904 | 1 × 79.904 = 79.904 C (carbon) | 10 | 12.011 | 10 × 12.011 = 120.110 Cl (chlorine) | 2 | 35.45 | 2 × 35.45 = 70.90 H (hydrogen) | 12 | 1.008 | 12 × 1.008 = 12.096 O (oxygen) | 3 | 15.999 | 3 × 15.999 = 47.997 P (phosphorus) | 1 | 30.973761998 | 1 × 30.973761998 = 30.973761998 S (sulfur) | 1 | 32.06 | 1 × 32.06 = 32.06 M = 79.904 g/mol + 120.110 g/mol + 70.90 g/mol + 12.096 g/mol + 47.997 g/mol + 30.973761998 g/mol + 32.06 g/mol = 394.04 g/mol
Unit conversion
0.394 kg/mol (kilograms per mole)
Comparisons
≈ 0.55 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 2 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 6.7 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 6.5×10^-22 grams | 6.5×10^-25 kg (kilograms) | 394 u (unified atomic mass units) | 394 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 394