A sample of zinc metal was reacted with an excess of hydrochloric acid.
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
All of the zinc reacted, and the hydrogen gas was collected over water at 17oC; the barometric pressure was 751 mmHg. The apparatus was similar to that shown in Figure 5.20, but the level of water inside the tube was 31.0 cm above the level outside the tube. If the volume of gas in the tube is 22.1 mL, how many grams of zinc were there in the sample?