posted by Bill .
A 0.528 gram sample of a metal, M, reacts completely with sulfuric acid according to: M+H2SO4 -> MSO4+H2
A volume of 205 mL of hydrogen is collected over water; the water level in the collecting vessel is the same as the outside level. Atmospheric pressure is 756.0 Torr and the temperature is 25°C. Calculate the atomic mass of the metal.
PV = nRT and solve for n = number of mols of H2. In the process one should reduce the total P by vapor pressure of H2O at 25C; however, that information is not included in the problem.
Then n mols H2 = same mols M, then
grams = mols/molar mass. You know grams and mols, solve for molar (atomic) mass M.
Is the answer 3.24x10^-3 g/mol?