Input interpretation
L-phenylalanine | molecular mass
Result
Find the molecular mass, m, for L-phenylalanine: 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_6H_5CH_2CH(NH_2)CO_2H Use the chemical formula, C_6H_5CH_2CH(NH_2)CO_2H, to count the number of atoms, N_i, for each element: | N_i C (carbon) | 9 H (hydrogen) | 11 N (nitrogen) | 1 O (oxygen) | 2 Look up the atomic mass, m_i, in unified atomic mass units, u, for each element in the periodic table: | N_i | m_i/u C (carbon) | 9 | 12.011 H (hydrogen) | 11 | 1.008 N (nitrogen) | 1 | 14.007 O (oxygen) | 2 | 15.999 Multiply N_i by m_i to compute the mass for each element. Then sum those values to compute the molecular mass, m: Answer: | | | N_i | m_i/u | mass/u C (carbon) | 9 | 12.011 | 9 × 12.011 = 108.099 H (hydrogen) | 11 | 1.008 | 11 × 1.008 = 11.088 N (nitrogen) | 1 | 14.007 | 1 × 14.007 = 14.007 O (oxygen) | 2 | 15.999 | 2 × 15.999 = 31.998 m = 108.099 u + 11.088 u + 14.007 u + 31.998 u = 165.192 u
Unit conversions
165.19 Da (daltons)
0.16519 kDa (kilodaltons)
2.7431×10^-22 grams
2.7431×10^-25 kg (kilograms)
165.2 chemical atomic mass units (unit officially deprecated)
165.24 physical atomic mass units (unit officially deprecated)
Comparisons as mass of molecule
≈ ( 0.23 ≈ 1/4 ) × molecular mass of fullerene ( ≈ 721 u )
≈ 0.85 × molecular mass of caffeine ( ≈ 194 u )
≈ 2.8 × molecular mass of sodium chloride ( ≈ 58 u )
Corresponding quantities
Relative atomic mass A_r from A_r = m_aN_A/M_u: | 165
Molar mass M from M = m_aN_A: | 165 g/mol (grams per mole)
Relative molecular mass M_r from M_r = m_mN_A/M_u: | 165
Molar mass M from M = m_mN_A: | 165 g/mol (grams per mole)