Input interpretation
![potassium hydroxide | molar mass](../image_source/da99b520453ab8d9ef63343a7bd5c2e0.png)
potassium hydroxide | molar mass
Result
![Find the molar mass, M, for potassium hydroxide: 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: KOH Use the chemical formula to count the number of atoms, N_i, for each element: | number of atoms H (hydrogen) | 1 K (potassium) | 1 O (oxygen) | 1 Look up the atomic mass, m_i, in g·mol^(-1) for each element in the periodic table: | number of atoms | atomic mass/g·mol^(-1) H (hydrogen) | 1 | 1.008 K (potassium) | 1 | 39.0983 O (oxygen) | 1 | 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: | | | number of atoms | atomic mass/g·mol^(-1) | mass/g·mol^(-1) H (hydrogen) | 1 | 1.008 | 1 × 1.008 = 1.008 K (potassium) | 1 | 39.0983 | 1 × 39.0983 = 39.0983 O (oxygen) | 1 | 15.999 | 1 × 15.999 = 15.999 M = 1.008 g/mol + 39.0983 g/mol + 15.999 g/mol = 56.105 g/mol](../image_source/bc90a9164c4b0cc3899462c8c106fa2f.png)
Find the molar mass, M, for potassium hydroxide: 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: KOH Use the chemical formula to count the number of atoms, N_i, for each element: | number of atoms H (hydrogen) | 1 K (potassium) | 1 O (oxygen) | 1 Look up the atomic mass, m_i, in g·mol^(-1) for each element in the periodic table: | number of atoms | atomic mass/g·mol^(-1) H (hydrogen) | 1 | 1.008 K (potassium) | 1 | 39.0983 O (oxygen) | 1 | 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: | | | number of atoms | atomic mass/g·mol^(-1) | mass/g·mol^(-1) H (hydrogen) | 1 | 1.008 | 1 × 1.008 = 1.008 K (potassium) | 1 | 39.0983 | 1 × 39.0983 = 39.0983 O (oxygen) | 1 | 15.999 | 1 × 15.999 = 15.999 M = 1.008 g/mol + 39.0983 g/mol + 15.999 g/mol = 56.105 g/mol
Unit conversion
![0.056105 kg/mol (kilograms per mole)](../image_source/4077cc49879fe18e98bc3031887b77e2.png)
0.056105 kg/mol (kilograms per mole)
Comparisons
![≈ ( 0.078 ≈ 1/13 ) × molar mass of fullerene (≈ 721 g/mol )](../image_source/2b2ed5d255b0c94374eeccc7692330ca.png)
≈ ( 0.078 ≈ 1/13 ) × molar mass of fullerene (≈ 721 g/mol )
![≈ 0.29 × molar mass of caffeine (≈ 194 g/mol )](../image_source/b9a6004a3ba1c7ea46b0917c0c22e3da.png)
≈ 0.29 × molar mass of caffeine (≈ 194 g/mol )
![≈ 0.96 × molar mass of sodium chloride (≈ 58 g/mol )](../image_source/165add204b589ded5c8e4c4f11562bab.png)
≈ 0.96 × molar mass of sodium chloride (≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 9.3×10^-23 grams | 9.3×10^-26 kg (kilograms) | 56 u (unified atomic mass units) | 56 Da (daltons)](../image_source/7d9891f579c6288ba6a375e1d2237ca2.png)
Mass of a molecule m from m = M/N_A: | 9.3×10^-23 grams | 9.3×10^-26 kg (kilograms) | 56 u (unified atomic mass units) | 56 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 56](../image_source/5d923117823d2eaa253a232a36fd4030.png)
Relative molecular mass M_r from M_r = M_u/M: | 56