Input interpretation
2, 2, 4-trimethylpentane | molar mass
Result
Find the molar mass, M, for 2, 2, 4-trimethylpentane: 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)_2CHCH_2C(CH_3)_3 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i C (carbon) | 8 H (hydrogen) | 18 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) C (carbon) | 8 | 12.011 H (hydrogen) | 18 | 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) C (carbon) | 8 | 12.011 | 8 × 12.011 = 96.088 H (hydrogen) | 18 | 1.008 | 18 × 1.008 = 18.144 M = 96.088 g/mol + 18.144 g/mol = 114.232 g/mol
Unit conversion
0.11423 kg/mol (kilograms per mole)
Comparisons
≈ ( 0.16 ≈ 1/6 ) × molar mass of fullerene ( ≈ 721 g/mol )
≈ 0.59 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 2 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 1.9×10^-22 grams | 1.9×10^-25 kg (kilograms) | 114 u (unified atomic mass units) | 114 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 114