A common way to make hydrogen gas in the laboratory is to place a metal such as zinc in hydrochloric acid. The hydrochloric acid reacts with the metal to produce hydrogen gas, which is then collected over water. Suppose a student carries out this reaction and collects a total of 1544 ml o gas at a pressure of 742 mmg and a temperature of 25\deg C. What mass of hydrogen gas (in mg) does the student collect?