Input interpretation
![molybdenum trioxide | molar mass](../image_source/2726fa2a4f9be72b9e43934df0169bdf.png)
molybdenum trioxide | molar mass
Result
![Find the molar mass, M, for molybdenum trioxide: 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: MoO_3 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Mo (molybdenum) | 1 O (oxygen) | 3 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) Mo (molybdenum) | 1 | 95.95 O (oxygen) | 3 | 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) Mo (molybdenum) | 1 | 95.95 | 1 × 95.95 = 95.95 O (oxygen) | 3 | 15.999 | 3 × 15.999 = 47.997 M = 95.95 g/mol + 47.997 g/mol = 143.95 g/mol](../image_source/1592da52e391467a7d432e104cc43caa.png)
Find the molar mass, M, for molybdenum trioxide: 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: MoO_3 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Mo (molybdenum) | 1 O (oxygen) | 3 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) Mo (molybdenum) | 1 | 95.95 O (oxygen) | 3 | 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) Mo (molybdenum) | 1 | 95.95 | 1 × 95.95 = 95.95 O (oxygen) | 3 | 15.999 | 3 × 15.999 = 47.997 M = 95.95 g/mol + 47.997 g/mol = 143.95 g/mol
Unit conversion
![0.1439 kg/mol (kilograms per mole)](../image_source/32242f2f09a58780e26c96653ce1796a.png)
0.1439 kg/mol (kilograms per mole)
Comparisons
![≈ ( 0.2 ≈ 1/5 ) × molar mass of fullerene ( ≈ 721 g/mol )](../image_source/70fdd3bcfe72c625240a479b657b2990.png)
≈ ( 0.2 ≈ 1/5 ) × molar mass of fullerene ( ≈ 721 g/mol )
![≈ 0.74 × molar mass of caffeine ( ≈ 194 g/mol )](../image_source/887b01ec0239d804cd2bcccd6fa64709.png)
≈ 0.74 × molar mass of caffeine ( ≈ 194 g/mol )
![≈ 2.5 × molar mass of sodium chloride ( ≈ 58 g/mol )](../image_source/a31701d936c65bc92f03a84e6994bcf1.png)
≈ 2.5 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 2.4×10^-22 grams | 2.4×10^-25 kg (kilograms) | 144 u (unified atomic mass units) | 144 Da (daltons)](../image_source/cf24ab419b7ddcec47e81c1bad2d6622.png)
Mass of a molecule m from m = M/N_A: | 2.4×10^-22 grams | 2.4×10^-25 kg (kilograms) | 144 u (unified atomic mass units) | 144 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 144](../image_source/8cda5c64b303a3ac63a2edf4bd9830e6.png)
Relative molecular mass M_r from M_r = M_u/M: | 144