Input interpretation
lithium thiocyanate hydrate | molar mass
Result
Find the molar mass, M, for lithium thiocyanate hydrate: 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: LiSCN·xH_2O Use the chemical formula, LiSCN·xH_2O, to count the number of atoms, N_i, for each element: | N_i C (carbon) | 1 H (hydrogen) | 2 Li (lithium) | 1 N (nitrogen) | 1 O (oxygen) | 1 S (sulfur) | 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) C (carbon) | 1 | 12.011 H (hydrogen) | 2 | 1.008 Li (lithium) | 1 | 6.94 N (nitrogen) | 1 | 14.007 O (oxygen) | 1 | 15.999 S (sulfur) | 1 | 32.06 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) C (carbon) | 1 | 12.011 | 1 × 12.011 = 12.011 H (hydrogen) | 2 | 1.008 | 2 × 1.008 = 2.016 Li (lithium) | 1 | 6.94 | 1 × 6.94 = 6.94 N (nitrogen) | 1 | 14.007 | 1 × 14.007 = 14.007 O (oxygen) | 1 | 15.999 | 1 × 15.999 = 15.999 S (sulfur) | 1 | 32.06 | 1 × 32.06 = 32.06 M = 12.011 g/mol + 2.016 g/mol + 6.94 g/mol + 14.007 g/mol + 15.999 g/mol + 32.06 g/mol = 83.03 g/mol
Unit conversion
0.083 kg/mol (kilograms per mole)
Comparisons
≈ ( 0.12 ≈ 1/9 ) × molar mass of fullerene ( ≈ 721 g/mol )
≈ 0.43 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 1.4 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 1.4×10^-22 grams | 1.4×10^-25 kg (kilograms) | 83 u (unified atomic mass units) | 83 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 83