Answer to Question #295700 in General Chemistry for Favy

Question

If 6.5 gram of magnesium ribbon reacts completely with hydrochloric acid how many grams of H2 will be liberate (H=1,Mg=24)

Answer 1

The reaction that occurs is

$Mg_{(s)}+2HCl_{(ac)} \to H_{2(g)}+MgCl_{2(ac)}$

We use the mass of Mg to find how much H₂ was produced

$\text{6.5 g Mg}\,(\frac{\text{1 mol Mg}}{\text{24.0 g Mg}})(\frac{\text{1 mol H}_2}{\text{1 mol Mg}})(\frac{\text{2 g H}_2}{\text{1 mol H}_2}) \\ = \text{0.5417 g H}_2$

In conclusion, 0.5417 g of H_2(g) are produced.