Thermodynamics and Stoichiometry of a Reaction Data Analysis Presentation of Data:

Trial 1 Trial 2 Trial 3

mass of Mg ribbon:

volume of H2 produced:

initial temperature of HCl solution:

final temperature of HCl solution: 37.8, 36.0, 37.7

atmospheric pressure:

Calculations:

1.

Write the molecular equation for the reaction that was carried out.

2.

Write the complete ionic equation for the reaction that was carried out.

3.

Write the net ionic equation for the reaction that was carried out.

4.

Calculate the mass of the number of moles of magnesium that were used in each trial.

5.

Calculate the number of moles of H2 gas that should be produced stoichiometrically by the magnesium metal used in each trial. The HCl is the limiting reagent in all these reactions.

6.

Calculate the volume of H2 gas that should be produced stoichiometrically by the magnesium metal used in each trial. Use the results of question 5 and the ideal gas law.

7.

Calculate the percent error between the predicted and measured volumes of H2 produced in each trial.

8.

Using the measured temperature change, calculate the molar enthalpy of the reaction in each trial. (q = mcT)

9.

Using standard enthalpies of formation for the reactants and products, calculate the theoretical standard molar enthalpy of the reaction.

10.

Calculate the percent error between the predicted and measured standard enthalpies of reaction in each trial.