Input interpretation
![2-methylheptadecane | molar mass](../image_source/261e5852c0b26b044974758aa0b4ecba.png)
2-methylheptadecane | molar mass
Result
![Find the molar mass, M, for 2-methylheptadecane: 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_18H_38 Use the chemical formula, C_18H_38, to count the number of atoms, N_i, for each element: | N_i C (carbon) | 18 H (hydrogen) | 38 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) | 18 | 12.011 H (hydrogen) | 38 | 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) | 18 | 12.011 | 18 × 12.011 = 216.198 H (hydrogen) | 38 | 1.008 | 38 × 1.008 = 38.304 M = 216.198 g/mol + 38.304 g/mol = 254.502 g/mol](../image_source/c9752e80534a34acf6feafc2eb01601b.png)
Find the molar mass, M, for 2-methylheptadecane: 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_18H_38 Use the chemical formula, C_18H_38, to count the number of atoms, N_i, for each element: | N_i C (carbon) | 18 H (hydrogen) | 38 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) | 18 | 12.011 H (hydrogen) | 38 | 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) | 18 | 12.011 | 18 × 12.011 = 216.198 H (hydrogen) | 38 | 1.008 | 38 × 1.008 = 38.304 M = 216.198 g/mol + 38.304 g/mol = 254.502 g/mol
Unit conversion
![0.2545 kg/mol (kilograms per mole)](../image_source/7fcee49b62921077e49a01aa63fa0513.png)
0.2545 kg/mol (kilograms per mole)
Comparisons
![≈ 0.35 × molar mass of fullerene ( ≈ 721 g/mol )](../image_source/85a00aa369ca771bc35b3c6d447b7f91.png)
≈ 0.35 × molar mass of fullerene ( ≈ 721 g/mol )
![≈ 1.3 × molar mass of caffeine ( ≈ 194 g/mol )](../image_source/a47cb5e8cd3c4a0e129bbb44b1a4a6a2.png)
≈ 1.3 × molar mass of caffeine ( ≈ 194 g/mol )
![≈ 4.4 × molar mass of sodium chloride ( ≈ 58 g/mol )](../image_source/adc168918ea873c313472a39ce4962a4.png)
≈ 4.4 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 4.2×10^-22 grams | 4.2×10^-25 kg (kilograms) | 255 u (unified atomic mass units) | 255 Da (daltons)](../image_source/01d1531d5a8a442b459fb700ecab370f.png)
Mass of a molecule m from m = M/N_A: | 4.2×10^-22 grams | 4.2×10^-25 kg (kilograms) | 255 u (unified atomic mass units) | 255 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 255](../image_source/da8eded9e0321c9ea3b219cdb7bd0ee3.png)
Relative molecular mass M_r from M_r = M_u/M: | 255