Input interpretation
dilithium tetrabromonickelate(II) | molar mass
Result
Find the molar mass, M, for dilithium tetrabromonickelate(II): 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: Li_2NiBr_4 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Br (bromine) | 4 Li (lithium) | 2 Ni (nickel) | 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) Br (bromine) | 4 | 79.904 Li (lithium) | 2 | 6.94 Ni (nickel) | 1 | 58.6934 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) Br (bromine) | 4 | 79.904 | 4 × 79.904 = 319.616 Li (lithium) | 2 | 6.94 | 2 × 6.94 = 13.88 Ni (nickel) | 1 | 58.6934 | 1 × 58.6934 = 58.6934 M = 319.616 g/mol + 13.88 g/mol + 58.6934 g/mol = 392.19 g/mol
Unit conversion
0.3922 kg/mol (kilograms per mole)
Comparisons
≈ 0.54 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 2 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 6.7 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 6.5×10^-22 grams | 6.5×10^-25 kg (kilograms) | 392 u (unified atomic mass units) | 392 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 392