Combined Gas Law and Stoichiometry LAB….MakeUp ...

Combined Gas Law and StoichiometryReplacement of Hydrogen by a MetalName____________________________________Pd______Temperature of hydrogen gas collected- 22.5 o C = _________KVolume of hydrogen gas collected (Actual Yield) 44.0 mL = _________LMass of magnesium strip-0.0358 gBarometer reading-748 mmHgVapor pressure of water at observed temperature-*refer to Table A-8 (p. 859 of text)______________mmHgCALCULATIONS: SHOW ALL YOUR WORK1. Balanced reaction: _____ Mg (s) + ____ HCl (aq) -----------------------------------------------------------------------------------------------------------2. Calculate the theoretical yield for the volume of hydrogen gas at STP. (Hint – Stoichiometry –Show all Work)Theoretical yield at STP= __________L3. Use Dalton’s Law of Partial Pressure, calculate the pressure of the dry hydrogen gas collected by waterdisplacement? (Hint: Subtract the pressure of the water pressure from the room pressure.)P TOTAL = P ROOM = PP HYDROGEN + PP WATER VAPORPressure of dry gas = ___________mm HgPART A: Using the COMBINED GAS LAW4..Using the Combined Gas Law, calculate the actual volume of hydrogen gas at standard temperature andstandard atmospheric pressure: (Hint: Solve for V 2 at STP…Real conditions are your initial T and P.)5. Percent Yield at STP:% Yield = Actual Yield X 100Theoretical YieldActual Yield at STP = _____________L% Yield __________6. Percent Error at STP%Error = | Theoretical Yield – Actual Yield | X 100Theoretical Yield% Error ___________

Part B: Using the IDEAL GAS LAW. – NOT AT STP CONDITIONS - USE ROOM CONDITIONSFrom your data Table, the actual yield = ___________L1. Using the Ideal Gas Law, calculate the volume of gas that should have been produced (theoretical yield).PV=nRT or PV=mRT/MM2. Percent Yield% Yield = Actual Yield X 100Theoretical YieldTheoretical Yield______________ L H 2% Yield ________________3. Percent Error%Error = | Theoretical Yield – Actual Yield | X 100Theoretical Yield% Error _________________Analysis:11. In part A, which was bigger, the theoretical yield (at STP) or the theoretical yield (at true conditions)? Explain.Theoretical Yield ______________12. In part B, which was bigger, the theoretical yield (at real conditions) or the actual yield (lab result)? Explain.13. Based on your data, explain 2 sources of experimental error in your lab? (This does not include mathcalculations errors) Is the percent yield more than or less than 100? WHY?