In this experiment, the pressure of air was measured over a range of temperature

Question

In this experiment, the pressure of air was measured over a range of temperatures. In atmospheric air, there is an important gas called ozone with the chemical formula O_3. How many lone pairs are present in the Lewis structure of ozone? In preparing for this experiment, 3.0 M HCI was made from a stock solution of 12.0 M HCI. What procedure was most likely followed to end up with the 3.0 M solution? If 8.1 g of magnesium is reacted with 5.9 mL of 3.0 M HCI by the procedure described in this experiment, how many moles of hydrogen gas are produced?

Explanation / Answer

1] O3 is NOT an atom but a molecular of three atoms of oxygen (named OZONE)
Each oxygen has two bonds, one each to the other to oxygens., making for a triangular shaped molecule.
Similar to water, each oxygen has two lone pairs, so overall the O3(Ozone) molecule has 6 lone pairs

2]  It's a dilution problem. You can solve it by using the equation C1V1 = C2V2.

For example, if I wanted to take a solution of 12M HCl and make a 100 mL solution of 3 M HCl, I would set the equation of V1 = (C2V2)/C1, where C2 is 3M, V2 is 100 mL, and C1 is 12M. In this case (3 * 100)/12 = 25 mL. So you would need 25 mL of 12M nitric acid and 75 mL of water to make a 3M solution.

3] Mg + 2HCl ----> MgCl2 +H2

Moles of HCl = MV = 0.0177

Moles of Magnesium = 8.1 / 24.305 = 0.333

1 mole of Mg recats with 2 moles of HCl to produce 1 mole of H2

0.0177 mole of HCl would react completely with 0.0177 x (1/2) = 0.00885 mol of Mg, but there is more Mg present than that, so Mg is in excess and HCl is the limiting reactant.

(0.0177 mol HCl) x (1 mol H2 / 1 mol Mg) = 0.018 mol H2

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.