A sample of iron reacted with hydrochloric acid. The liberated hydrogen occupied 40.1 mL when collected over water at 27 C at a barometric pressure of 750 torr. What is the mass of the sample of iron? (Because of the collection of gas over water, the vapor pressure of the water must be subtracted from the barometric pressure to find the pressure of the hydrogen gas.)
Fe(s)+ 2HCl(aq)=FeCl2(aq)+ H2(g)