How many grams of hydrogen gas will be liberated when 6g of magnesium ribbon dissolves...
How many grams of hydrogen gas will be liberated when 6g of magnesium ribbon dissolves in 500cm3 of 6M HCl? (Mg = 24, H = 1, Cl = 33.57)
- A) 1.0
- B) 1.5
- C) 0.5
- D) 2.0
Correct Answer: C) 0.5
Explanation
Potassium trioxochlorate(V) has the chemical formula KClO3. When it decomposes, it produces potassium chloride (KCl) and oxygen gas (O2). The balanced chemical equation for this decomposition reaction is:
\(2KClO_3 \rightarrow 2KCl + 3O_2\)
From the balanced equation, we can see that 2 moles of potassium trioxochlorate(V) decompose to produce 3 moles of oxygen molecules. We are given that 2.5 moles of potassium trioxochlorate(V) decompose. To find the number of moles of oxygen molecules produced, we can use the stoichiometry of the balanced equation:
\(\frac{3 \, moles \, of \, O_2}{2 \, moles \, of \, KClO_3} = \frac{x \, moles \, of \, O_2}{2.5 \, moles \, of \, KClO_3}\)
To solve for x, which represents the number of moles of oxygen molecules produced, we can cross-multiply and divide:
\(x = \frac{3 \, moles \, of \, O_2 \times 2.5 \, moles \, of \, KClO_3}{2 \, moles \, of \, KClO_3} = 2.50 \, moles \, of \, O_2\)
Therefore, 2.50 moles of oxygen molecules would be produced from the decomposition of 2.5 moles of potassium trioxochlorate(V), making Option A the correct choice.