Input interpretation
![disodium hydrogen arsenate | molar mass](../image_source/c0e96269d3a8f993aefa19a49e19de30.png)
disodium hydrogen arsenate | molar mass
Result
![Find the molar mass, M, for disodium hydrogen arsenate: 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: AsHNa_2O_4 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i As (arsenic) | 1 H (hydrogen) | 1 Na (sodium) | 2 O (oxygen) | 4 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) As (arsenic) | 1 | 74.921595 H (hydrogen) | 1 | 1.008 Na (sodium) | 2 | 22.98976928 O (oxygen) | 4 | 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) As (arsenic) | 1 | 74.921595 | 1 × 74.921595 = 74.921595 H (hydrogen) | 1 | 1.008 | 1 × 1.008 = 1.008 Na (sodium) | 2 | 22.98976928 | 2 × 22.98976928 = 45.97953856 O (oxygen) | 4 | 15.999 | 4 × 15.999 = 63.996 M = 74.921595 g/mol + 1.008 g/mol + 45.97953856 g/mol + 63.996 g/mol = 185.905 g/mol](../image_source/ca52275c66952fa339716aa6b2252615.png)
Find the molar mass, M, for disodium hydrogen arsenate: 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: AsHNa_2O_4 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i As (arsenic) | 1 H (hydrogen) | 1 Na (sodium) | 2 O (oxygen) | 4 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) As (arsenic) | 1 | 74.921595 H (hydrogen) | 1 | 1.008 Na (sodium) | 2 | 22.98976928 O (oxygen) | 4 | 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) As (arsenic) | 1 | 74.921595 | 1 × 74.921595 = 74.921595 H (hydrogen) | 1 | 1.008 | 1 × 1.008 = 1.008 Na (sodium) | 2 | 22.98976928 | 2 × 22.98976928 = 45.97953856 O (oxygen) | 4 | 15.999 | 4 × 15.999 = 63.996 M = 74.921595 g/mol + 1.008 g/mol + 45.97953856 g/mol + 63.996 g/mol = 185.905 g/mol
Unit conversion
![0.18591 kg/mol (kilograms per mole)](../image_source/556cb2c42720898ff6f853b88936f6aa.png)
0.18591 kg/mol (kilograms per mole)
Comparisons
![≈ 0.26 × molar mass of fullerene ( ≈ 721 g/mol )](../image_source/5263a37de49afa8d4cf308e73ff717f9.png)
≈ 0.26 × molar mass of fullerene ( ≈ 721 g/mol )
![≈ 0.96 × molar mass of caffeine ( ≈ 194 g/mol )](../image_source/e7904be7ccf7eb36cbd072a410890e54.png)
≈ 0.96 × molar mass of caffeine ( ≈ 194 g/mol )
![≈ 3.2 × molar mass of sodium chloride ( ≈ 58 g/mol )](../image_source/6fcd72b998f6f3c6dac8f334ebdd8bca.png)
≈ 3.2 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
![Mass of a molecule m from m = M/N_A: | 3.1×10^-22 grams | 3.1×10^-25 kg (kilograms) | 186 u (unified atomic mass units) | 186 Da (daltons)](../image_source/17b6f39ab0d069bb671c6b7d84ded272.png)
Mass of a molecule m from m = M/N_A: | 3.1×10^-22 grams | 3.1×10^-25 kg (kilograms) | 186 u (unified atomic mass units) | 186 Da (daltons)
![Relative molecular mass M_r from M_r = M_u/M: | 186](../image_source/3df478353ef9a320e2b646484e23b731.png)
Relative molecular mass M_r from M_r = M_u/M: | 186