Input interpretation
![calcium hydroxide | molar mass](../image_source/54b357a9b01eb586b8531d36b21f008d.png)
calcium hydroxide | molar mass
Result
![Find the molar mass, M, for calcium 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: Ca(OH)_2 Use the chemical formula to count the number of atoms, N_i, for each element: | number of atoms Ca (calcium) | 1 H (hydrogen) | 2 O (oxygen) | 2 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) Ca (calcium) | 1 | 40.078 H (hydrogen) | 2 | 1.008 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: | | | number of atoms | atomic mass/g·mol^(-1) | mass/g·mol^(-1) Ca (calcium) | 1 | 40.078 | 1 × 40.078 = 40.078 H (hydrogen) | 2 | 1.008 | 2 × 1.008 = 2.016 O (oxygen) | 2 | 15.999 | 2 × 15.999 = 31.998 M = 40.078 g/mol + 2.016 g/mol + 31.998 g/mol = 74.092 g/mol](../image_source/3114d1f0b2cdc45635410e4c75ad62d7.png)
Find the molar mass, M, for calcium 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: Ca(OH)_2 Use the chemical formula to count the number of atoms, N_i, for each element: | number of atoms Ca (calcium) | 1 H (hydrogen) | 2 O (oxygen) | 2 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) Ca (calcium) | 1 | 40.078 H (hydrogen) | 2 | 1.008 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: | | | number of atoms | atomic mass/g·mol^(-1) | mass/g·mol^(-1) Ca (calcium) | 1 | 40.078 | 1 × 40.078 = 40.078 H (hydrogen) | 2 | 1.008 | 2 × 1.008 = 2.016 O (oxygen) | 2 | 15.999 | 2 × 15.999 = 31.998 M = 40.078 g/mol + 2.016 g/mol + 31.998 g/mol = 74.092 g/mol
Unit conversion
![0.074092 kg/mol (kilograms per mole)](../image_source/81c19f3595a926f3be4f98764c088d5b.png)
0.074092 kg/mol (kilograms per mole)
Comparisons
![≈ ( 0.1 ≈ 1/10 ) × molar mass of fullerene (≈ 721 g/mol )](../image_source/331143cd98af1ca6837cfd86ffbcf15c.png)
≈ ( 0.1 ≈ 1/10 ) × molar mass of fullerene (≈ 721 g/mol )
![≈ 0.38 × molar mass of caffeine (≈ 194 g/mol )](../image_source/3306ff944e350304c840758590a02c2a.png)
≈ 0.38 × molar mass of caffeine (≈ 194 g/mol )
![≈ 1.3 × molar mass of sodium chloride (≈ 58 g/mol )](../image_source/1e37b7219b3de118db47c87077191f13.png)
≈ 1.3 × molar mass of sodium chloride (≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 1.2×10^-22 grams | 1.2×10^-25 kg (kilograms) | 74 u (unified atomic mass units) | 74 Da (daltons)](../image_source/d826c9f90d20f423a31d4f0393b9f6de.png)
Mass of a molecule m from m = M/N_A: | 1.2×10^-22 grams | 1.2×10^-25 kg (kilograms) | 74 u (unified atomic mass units) | 74 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 74](../image_source/45ccd6fcc03f7d9011e7f5e52034adca.png)
Relative molecular mass M_r from M_r = M_u/M: | 74