References:
Ebbing, "General Chemistry", 5th ed., pp.183-193, pp. 199-203 (Empirical gas laws, Ideal gas law, Gas stoichiometry, Dalton's law, gases collected over water)

Learning Center:
SSM Lesson 8 (pp. 110),(Dalton's law); WEN Module 10 (problems 1,2,3,4,9); answers to pre and post-lab questions.

SHOW SET-UP FOR ALL PROBLEMS

A student collected 115.7 mL of hydrogen (H2) over water at 763.3 torr atmospheric pressure and 18.6 °C. The mass of Zn metal used to generate the H2 was 0.329 g.

1A. (1) Use the table in Appendix B and the method of interpolation to determine the vapor pressure of water at 18.6°C. (2) Use Dalton's Law to calculate the partial pressure of H2 in the experiment.

1B. Convert the experimental volume of dry hydrogen measured under the conditions above to the volume that would have been observed at STP (0 °C and 760 torr).

1C. Write the balanced net ionic equation for the unbalanced molecular Equation 5.

1D. Calculate the number of moles of H2 gas from the mass of Zn metal used. Calculate the molar volume (L/mol ) of hydrogen at STP from the data above (Equation 5). Determine the percentage error in Vm. (The accepted theoretical Vm is 22.414 L/mol at STP). (Use extra page if necessary).

2. Why must the graduated cylinder be free of air bubbles prior to generating the H2 gas?

3. The volume of a certain mass of gas is 63 mL at 773 torr. What will be the volume of the gas if the pressure is decreased to 124 torr without changing the temperature?