Input interpretation
trans, trans-farnesyl bromide | molar mass
Result
![Find the molar mass, M, for trans, trans-farnesyl bromide: 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: (CH_3)_2C=CH[CH_2CH_2C(CH_3)=CH]_2CH_2Br Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 1 C (carbon) | 15 H (hydrogen) | 25 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) | 15 | 12.011 H (hydrogen) | 25 | 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) | 1 | 79.904 | 1 × 79.904 = 79.904 C (carbon) | 15 | 12.011 | 15 × 12.011 = 180.165 H (hydrogen) | 25 | 1.008 | 25 × 1.008 = 25.200 M = 79.904 g/mol + 180.165 g/mol + 25.200 g/mol = 285.269 g/mol](../image_source/fd72781263631cb11847fec0004ed4d6.png)
Find the molar mass, M, for trans, trans-farnesyl bromide: 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: (CH_3)_2C=CH[CH_2CH_2C(CH_3)=CH]_2CH_2Br Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 1 C (carbon) | 15 H (hydrogen) | 25 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) | 15 | 12.011 H (hydrogen) | 25 | 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) | 1 | 79.904 | 1 × 79.904 = 79.904 C (carbon) | 15 | 12.011 | 15 × 12.011 = 180.165 H (hydrogen) | 25 | 1.008 | 25 × 1.008 = 25.200 M = 79.904 g/mol + 180.165 g/mol + 25.200 g/mol = 285.269 g/mol
Unit conversion
0.28527 kg/mol (kilograms per mole)
Comparisons
≈ 0.4 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 1.5 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 4.9 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 4.7×10^-22 grams | 4.7×10^-25 kg (kilograms) | 285 u (unified atomic mass units) | 285 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 285