Input interpretation
![phosphorus(V) selenide | molar mass](../image_source/4e4f7c82aa88733e562bfee50f501bc5.png)
phosphorus(V) selenide | molar mass
Result
![Find the molar mass, M, for phosphorus(V) selenide: 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: P_2Se_5 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i P (phosphorus) | 1 Se (selenium) | 1 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) P (phosphorus) | 1 | 30.973761998 Se (selenium) | 1 | 78.971 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) P (phosphorus) | 1 | 30.973761998 | 1 × 30.973761998 = 30.973761998 Se (selenium) | 1 | 78.971 | 1 × 78.971 = 78.971 M = 30.973761998 g/mol + 78.971 g/mol = 109.945 g/mol](../image_source/3dfb84234b7dbb8dffed2f4e9574ac45.png)
Find the molar mass, M, for phosphorus(V) selenide: 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: P_2Se_5 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i P (phosphorus) | 1 Se (selenium) | 1 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) P (phosphorus) | 1 | 30.973761998 Se (selenium) | 1 | 78.971 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) P (phosphorus) | 1 | 30.973761998 | 1 × 30.973761998 = 30.973761998 Se (selenium) | 1 | 78.971 | 1 × 78.971 = 78.971 M = 30.973761998 g/mol + 78.971 g/mol = 109.945 g/mol
Unit conversion
![0.10994 kg/mol (kilograms per mole)](../image_source/b5de5944f43279732e039843fb0aa354.png)
0.10994 kg/mol (kilograms per mole)
Comparisons
![≈ ( 0.15 ≈ 1/7 ) × molar mass of fullerene ( ≈ 721 g/mol )](../image_source/91ab07b53975d6fb6659582b7f89d58f.png)
≈ ( 0.15 ≈ 1/7 ) × molar mass of fullerene ( ≈ 721 g/mol )
![≈ 0.57 × molar mass of caffeine ( ≈ 194 g/mol )](../image_source/dc1e80e1e7e84ca9b3ed72f4b7d6308a.png)
≈ 0.57 × molar mass of caffeine ( ≈ 194 g/mol )
![≈ 1.9 × molar mass of sodium chloride ( ≈ 58 g/mol )](../image_source/be363e658494b651663eb6749711eeae.png)
≈ 1.9 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 1.8×10^-22 grams | 1.8×10^-25 kg (kilograms) | 110 u (unified atomic mass units) | 110 Da (daltons)](../image_source/472247d06847168b5247f73ec68a7bf4.png)
Mass of a molecule m from m = M/N_A: | 1.8×10^-22 grams | 1.8×10^-25 kg (kilograms) | 110 u (unified atomic mass units) | 110 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 110](../image_source/8c0527a891435e80f7ceb42ab3aac986.png)
Relative molecular mass M_r from M_r = M_u/M: | 110