Input interpretation
![potassium peroxide | molar mass](../image_source/8c13f7f4e14145d15805c0bbb4241585.png)
potassium peroxide | molar mass
Result
![Find the molar mass, M, for potassium peroxide: 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: K_2O_2 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i K (potassium) | 2 O (oxygen) | 2 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) K (potassium) | 2 | 39.0983 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 molar mass, M: Answer: | | | N_i | m_i/g·mol^(-1) | mass/g·mol^(-1) K (potassium) | 2 | 39.0983 | 2 × 39.0983 = 78.1966 O (oxygen) | 2 | 15.999 | 2 × 15.999 = 31.998 M = 78.1966 g/mol + 31.998 g/mol = 110.195 g/mol](../image_source/e2a8def65344e746b820caeff0ce1da7.png)
Find the molar mass, M, for potassium peroxide: 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: K_2O_2 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i K (potassium) | 2 O (oxygen) | 2 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) K (potassium) | 2 | 39.0983 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 molar mass, M: Answer: | | | N_i | m_i/g·mol^(-1) | mass/g·mol^(-1) K (potassium) | 2 | 39.0983 | 2 × 39.0983 = 78.1966 O (oxygen) | 2 | 15.999 | 2 × 15.999 = 31.998 M = 78.1966 g/mol + 31.998 g/mol = 110.195 g/mol
Unit conversion
![0.11019 kg/mol (kilograms per mole)](../image_source/4715e0fbbd7306aec3f4e9b868765d7e.png)
0.11019 kg/mol (kilograms per mole)
Comparisons
![≈ ( 0.15 ≈ 1/7 ) × molar mass of fullerene ( ≈ 721 g/mol )](../image_source/368e967ede46a6b9a8a7e85093cfb06a.png)
≈ ( 0.15 ≈ 1/7 ) × molar mass of fullerene ( ≈ 721 g/mol )
![≈ 0.57 × molar mass of caffeine ( ≈ 194 g/mol )](../image_source/48884318192408d24891dec4de123e65.png)
≈ 0.57 × molar mass of caffeine ( ≈ 194 g/mol )
![≈ 1.9 × molar mass of sodium chloride ( ≈ 58 g/mol )](../image_source/11be3d4574b40c0688ff1b645248bec2.png)
≈ 1.9 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 1.8×10^-22 grams | 1.8×10^-25 kg (kilograms) | 110 u (unified atomic mass units) | 110 Da (daltons)](../image_source/1596d904978947c0fce47c24c77561a3.png)
Mass of a molecule m from m = M/N_A: | 1.8×10^-22 grams | 1.8×10^-25 kg (kilograms) | 110 u (unified atomic mass units) | 110 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 110](../image_source/22c0a3bc7c85509b24dd7a23f3e66cdd.png)
Relative molecular mass M_r from M_r = M_u/M: | 110