Input interpretation
thorium silicide | molar mass
Result
Find the molar mass, M, for thorium silicide: 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: Si_2Th Use the chemical formula to count the number of atoms, N_i, for each element: | N_i Si (silicon) | 2 Th (thorium) | 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) Si (silicon) | 2 | 28.085 Th (thorium) | 1 | 232.0377 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) Si (silicon) | 2 | 28.085 | 2 × 28.085 = 56.170 Th (thorium) | 1 | 232.0377 | 1 × 232.0377 = 232.0377 M = 56.170 g/mol + 232.0377 g/mol = 288.208 g/mol
Unit conversion
0.288208 kg/mol (kilograms per mole)
Comparisons
≈ 0.4 × molar mass of fullerene ( ≈ 721 g/mol )
≈ 1.5 × molar mass of caffeine ( ≈ 194 g/mol )
≈ 4.9 × molar mass of sodium chloride ( ≈ 58 g/mol )
Corresponding quantities
Mass of a molecule m from m = M/N_A: | 4.8×10^-22 grams | 4.8×10^-25 kg (kilograms) | 288 u (unified atomic mass units) | 288 Da (daltons)
Relative molecular mass M_r from M_r = M_u/M: | 288