Question

Magnesium metal reacts with hydrochloric acid to form magnesium chloride and hydrogen gas. Suppose we react an excess of magnesium metal with 13.2 mL of a 3.00 M solution of hydrochloric acid and collect all of the hydrogen in a balloon at 25oC and 1.00 atm. What is the expected volume of the balloon?
A) 40.6 L
B) 0.0406 L
C) 0.215 L
D) 0.484 L
E) 0.97 L

I got E as my answer but the CORRECT answer is D. I wanna know where I went wrong.

Answer 1

Mg + 2HCl --> MgCl2 + H2
#mol=molarity x volume
(3.00) x (.0132 L) = .0396 mol HCl
half this in accordance with you balanced chemical equation to get #mol H2 = .0198.
relate #mol of gas to volume --> (.0198) x (22.4) = 0.444...closest answer, (D.

Answer 2

j75