molar mass of nickel(II) nitrate hexahydrate

nickel(II) nitrate hexahydrate | molar mass

Find the molar mass, M, for nickel(II) nitrate hexahydrate: 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: [Ni(H_2O)_6](NO_3)_2 Use the chemical formula to count the number of atoms, N_i, for each element: | N_i H (hydrogen) | 12 N (nitrogen) | 2 Ni (nickel) | 1 O (oxygen) | 12 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) H (hydrogen) | 12 | 1.008 N (nitrogen) | 2 | 14.007 Ni (nickel) | 1 | 58.6934 O (oxygen) | 12 | 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) H (hydrogen) | 12 | 1.008 | 12 × 1.008 = 12.096 N (nitrogen) | 2 | 14.007 | 2 × 14.007 = 28.014 Ni (nickel) | 1 | 58.6934 | 1 × 58.6934 = 58.6934 O (oxygen) | 12 | 15.999 | 12 × 15.999 = 191.988 M = 12.096 g/mol + 28.014 g/mol + 58.6934 g/mol + 191.988 g/mol = 290.791 g/mol

0.29079 kg/mol (kilograms per mole)

≈ 0.4 × molar mass of fullerene ( ≈ 721 g/mol )

≈ 1.5 × molar mass of caffeine ( ≈ 194 g/mol )

≈ 5 × molar mass of sodium chloride ( ≈ 58 g/mol )

Mass of a molecule m from m = M/N_A: | 4.8×10^-22 grams | 4.8×10^-25 kg (kilograms) | 291 u (unified atomic mass units) | 291 Da (daltons)

Relative molecular mass M_r from M_r = M_u/M: | 291