Input interpretation
![barium peroxide | molar mass](../image_source/35345d355b9a55aa080dd92a3afda518.png)
barium peroxide | molar mass
Result
![Find the molar mass, M, for barium 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: BaO_2 Use the chemical formula, BaO_2, to count the number of atoms, N_i, for each element: | N_i Ba (barium) | 1 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) Ba (barium) | 1 | 137.327 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) Ba (barium) | 1 | 137.327 | 1 × 137.327 = 137.327 O (oxygen) | 2 | 15.999 | 2 × 15.999 = 31.998 M = 137.327 g/mol + 31.998 g/mol = 169.325 g/mol](../image_source/e8d67697635f7ecc85376b87fff04af2.png)
Find the molar mass, M, for barium 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: BaO_2 Use the chemical formula, BaO_2, to count the number of atoms, N_i, for each element: | N_i Ba (barium) | 1 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) Ba (barium) | 1 | 137.327 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) Ba (barium) | 1 | 137.327 | 1 × 137.327 = 137.327 O (oxygen) | 2 | 15.999 | 2 × 15.999 = 31.998 M = 137.327 g/mol + 31.998 g/mol = 169.325 g/mol
Unit conversion
![0.169325 kg/mol (kilograms per mole)](../image_source/ba7d32b130789464027610d01475cbb0.png)
0.169325 kg/mol (kilograms per mole)
Comparisons
![≈ ( 0.23 ≈ 1/4 ) × molar mass of fullerene ( ≈ 721 g/mol )](../image_source/e90a16bcf58add08bd32e84e42eb6a6a.png)
≈ ( 0.23 ≈ 1/4 ) × molar mass of fullerene ( ≈ 721 g/mol )
![≈ 0.87 × molar mass of caffeine ( ≈ 194 g/mol )](../image_source/02be74325dc55ddd26c0c96e1ae7d3d6.png)
≈ 0.87 × molar mass of caffeine ( ≈ 194 g/mol )
![≈ 2.9 × molar mass of sodium chloride ( ≈ 58 g/mol )](../image_source/4e49cc198fd62775bac34df903ac57c1.png)
≈ 2.9 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 2.8×10^-22 grams | 2.8×10^-25 kg (kilograms) | 169 u (unified atomic mass units) | 169 Da (daltons)](../image_source/d72d4a4d3303f882bfb1d5699c4f4057.png)
Mass of a molecule m from m = M/N_A: | 2.8×10^-22 grams | 2.8×10^-25 kg (kilograms) | 169 u (unified atomic mass units) | 169 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 169](../image_source/231b8f5c211036192f9e64cd191ac031.png)
Relative molecular mass M_r from M_r = M_u/M: | 169