Ask Question
20 December, 07:12

Zinc and magnesium metal each reacts with hydrochloric acid to make chloride salts of the respective metals, and hydrogen gas. a 11.20-g mixture of zinc and magnesium produces 0.6854 g of hydrogen gas upon being mixed with an excess of hydrochloric acid. determine the percent magnesium by mass in the original mixture.

+1
Answers (1)
  1. 20 December, 07:19
    0
    M=11.20 g

    m (H₂) = 0.6854 g

    M (H₂) = 2.016 g/mol

    M (Mg) = 24.305 g/mol

    M (Zn) = 65.39 g/mol

    w-?

    m (Mg) = wm

    m (Zn) = (1-w) m

    Zn + 2HCl = ZnCl₂ + H₂

    m₁ (H₂) = M (H₂) m (Zn) / M (Zn) = M (H₂) (1-w) m/M (Zn)

    Mg + 2HCl = MgCl₂ + H₂

    m₂ (H₂) = M (H₂) m (Mg) / M (Mg) = M (H₂) wm/M (Mg)

    m (H₂) = m₁ (H₂) + m₂ (H₂)

    m (H₂) = M (H₂) (1-w) m/M (Zn) + M (H₂) wm/M (Mg) = M (H₂) m{ (1-w) / M (Zn) + w/M (Mg) }

    m (H₂) = M (H₂) m{ (1-w) / M (Zn) + w/M (Mg) }

    (1-w) / M (Zn) + w/M (Mg) = m (H₂) / {M (H₂) m}

    1/M (Zn) - w/M (Zn) + w/M (Mg) = m (H₂) / {M (H₂) m}

    w (1/M (Mg) - 1/M (Zn)) = m (H₂) / {M (H₂) m}-1/M (Zn)

    w=[m (H₂) / {M (H₂) m}-1/M (Zn) ] / (1/M (Mg) - 1/M (Zn))

    w=0.583 (58.3%)
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “Zinc and magnesium metal each reacts with hydrochloric acid to make chloride salts of the respective metals, and hydrogen gas. a 11.20-g ...” in 📗 Chemistry if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers