GAS LAws Data Analysis STOICHIOMETRY OF THE REACTION Prepare a calculation table

Question

GAS LAws Data Analysis STOICHIOMETRY OF THE REACTION Prepare a calculation table in your laboratory notebook similar to the one on page 84. Result Write a chemical equation to ilustrate your aver age experimental ratio of moles hydrogen per mole of Mg. Compare your equation with the theoretical balanced equation. Write a balanced chemical equation to represent the reaction between magnesium and hydrochloric acid Discussion Does your average experimental ratio between H2(93 mo'es of H, and Mg agree with the theoretical ra- For each reaction mixture, calculate the f and record in the calculation table. tio? If not, identify one major source of error in the process that might account for this difference. Moles magnesium reacted. Molarity of HCI used in the reaction for dilu- the reaction ratio between H, and Mg? Explain tions: M-(M.V./V, where "d" represents or ilustrate. dilute and "s" represents "stock." Does the concentration of HCI affect or change Volume of hydrogen gas produced. Pressure of dry Hfg) (apply Dalton's Law of time it took for complete reaction to occur? Would Partial Pressures; check your textbook for the amount of Mg also affect the time required for review if needed]. Does the concentration of HCl affect the amount of complete reaction? Explain. Lab Project Summary Report You and your partner are to prepare one lab Moles H) produced [Use the Ideal Gasreport following the guidelines and outine Law). Experimental reaction ratio (moles H, per 1 described on pages ix-x. Remember, it is your responsibility as part ners to ensure that everyone whose name is on the report participated as fully as possible in the project. mol Mg). Average your three experimental reaction ratios for moles H2 per 1 mol Mg and round to the nearest integer value.

Explanation / Answer

Reaction 1

Temperature = 24 + 373 = 297 K

Moles of Mg = mass/molecular weight

= 0.1221g / 24.305 g/mol = 0.00502 mol

Molarity of HCl = 4 M

Volume of H2 produced = 115 mL x 1L/1000 mL = 0.115 L

Pressure of dry H2 = Barometric pressure - Vapor pressure of water at 24 C

= 760 - 22.38

= 737.62 mmHg x 1atm /760mmHg

= 0.9705 atm

From the ideal gas equation

Moles of H2 produced = PV/RT

= 0.9705 atm x 0.115 L / 0.0821 L-atm/mol-K x 297 K

= 0.004577 mol

Mol H2 / mol Mg = 0.004577 mol H2 / 0.00502 mol Mg

= 0.9118 Mol H2 / mol Mg

Similarly for reaction 2

Temperature = 23 + 373 = 296 K

Moles of Mg = mass/molecular weight

= 0.1249g / 24.305 g/mol = 0.00514 mol

Molarity of HCl = 4 M

Volume of H2 produced = 130 mL x 1L/1000 mL = 0.130 L

Pressure of dry H2 = Barometric pressure - Vapor pressure of water at 23 C

= 760 - 19.83

= 740.17 mmHg x 1atm /760mmHg

= 0.9739 atm

From the ideal gas equation

Moles of H2 produced = PV/RT

= 0.9739 atm x 0.130 L / 0.0821 L-atm/mol-K x 296 K

= 0.005209 mol

Mol H2 / mol Mg = 0.005209 mol H2 / 0.00514 mol Mg

= 1.014 Mol H2 / mol Mg

Similarly for reaction 3

Temperature = 25 + 373 = 298 K

Moles of Mg = mass/molecular weight

= 0.1100g / 24.305 g/mol = 0.00453 mol

Molarity of HCl = 4 M

Volume of H2 produced = 110 mL x 1L/1000 mL = 0.110 L

Pressure of dry H2 = Barometric pressure - Vapor pressure of water at 25 C

= 760 - 25.21

= 734.79 mmHg x 1atm /760mmHg

= 0.9668 atm

From the ideal gas equation

Moles of H2 produced = PV/RT

= 0.9668 atm x 0.110 L / 0.0821 L-atm/mol-K x 298 K

= 0.004347 mol

Mol H2 / mol Mg = 0.004347 mol H2 / 0.00453 mol Mg

= 0.9595 Mol H2 / mol Mg

Average Mol H2 / mol Mg = (0.9595 + 1.014 + 0.9118)/3

= 2.8853/3

= 0.9618

Related Questions

Navigate

• Browse (All)
• Browse G
• Subjects

---

---

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