Andrea and her lab partner were conducting a variety of experiments to produce gases: hydrogen, oxygen, and carbon dioxide. In one experiment, they added a piece of magnesium ribbon to 10 milliliters of hydrochloric acid. They observed bubbles being produced and did a variety of tests to identify the escaping gas; it proved to be hydrogen. The reaction is represented by the following equation:
Mg + 2HCl → MgCl2 + H2(g)
If Andrea and her partner produced 0.250 mols H2, at STP, what is the mass of the hydrogen gas, in grams?
A) 0.253g
B) 0.505g
C) 2.183g
D) 4.044g