Input interpretation
![potassium persulfate | molar mass](../image_source/80e14aba4f203f869511c6a471c5c43f.png)
potassium persulfate | molar mass
Result
![Find the molar mass, M, for potassium persulfate: 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_2S_2O_8 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i K (potassium) | 2 O (oxygen) | 8 S (sulfur) | 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) | 8 | 15.999 S (sulfur) | 2 | 32.06 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) | 8 | 15.999 | 8 × 15.999 = 127.992 S (sulfur) | 2 | 32.06 | 2 × 32.06 = 64.12 M = 78.1966 g/mol + 127.992 g/mol + 64.12 g/mol = 270.31 g/mol](../image_source/d8a0a6fba87b1e2101652d7561b691ca.png)
Find the molar mass, M, for potassium persulfate: 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_2S_2O_8 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i K (potassium) | 2 O (oxygen) | 8 S (sulfur) | 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) | 8 | 15.999 S (sulfur) | 2 | 32.06 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) | 8 | 15.999 | 8 × 15.999 = 127.992 S (sulfur) | 2 | 32.06 | 2 × 32.06 = 64.12 M = 78.1966 g/mol + 127.992 g/mol + 64.12 g/mol = 270.31 g/mol
Unit conversion
![0.27031 kg/mol (kilograms per mole)](../image_source/adf362ded03dc73858258ae256e7129f.png)
0.27031 kg/mol (kilograms per mole)
Comparisons
![≈ 0.38 × molar mass of fullerene ( ≈ 721 g/mol )](../image_source/8e74ccef36f915ce6b2c15f8eeec67ad.png)
≈ 0.38 × molar mass of fullerene ( ≈ 721 g/mol )
![≈ 1.4 × molar mass of caffeine ( ≈ 194 g/mol )](../image_source/629f1e61ec127de63c4b19e2cf70faef.png)
≈ 1.4 × molar mass of caffeine ( ≈ 194 g/mol )
![≈ 4.6 × molar mass of sodium chloride ( ≈ 58 g/mol )](../image_source/26f8e4246363ed322bff30dd30e615c0.png)
≈ 4.6 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 4.5×10^-22 grams | 4.5×10^-25 kg (kilograms) | 270 u (unified atomic mass units) | 270 Da (daltons)](../image_source/07b3c3c960bee603f22ab5fdd0f78af8.png)
Mass of a molecule m from m = M/N_A: | 4.5×10^-22 grams | 4.5×10^-25 kg (kilograms) | 270 u (unified atomic mass units) | 270 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 270](../image_source/54c783c62fc990842d620cdfc8202423.png)
Relative molecular mass M_r from M_r = M_u/M: | 270