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Experiments of Chemistry

Experiments of Chemistry. By: Michelle Woosley. Rules of The Lab. Splash proof googles must be worn at all times! No food or drinks are allowed in the laboratory. Cover skin as much as possible; no open-toed shoes allowed.

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Experiments of Chemistry

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  1. Experiments of Chemistry By: Michelle Woosley

  2. Rules of The Lab • Splash proof googles must be worn at all times! • No food or drinks are allowed in the laboratory. • Cover skin as much as possible; no open-toed shoes allowed. • If you break any glassware inform your instructor immediately. Do not try to pick up the glass yourself. • If a chemical spill occurs inform your instructor immediately. Do not try to clean up the spill, we have a special kit to clean up spills. • At the end of each lab session clean the equipment and lab station for the next student. • ASU policy- NOTHING goes down the drain!! • Ask before you mix anything! One mistake and….

  3. What is a Copper Cycle? • The copper cycle – the process by which copper is processed, combined, and extracted from other compounds in order to recover pure copper. • Materials: • Copper Wire • 6 M HNO3 (aq) (Nitric Acid)* • 6 M NaOH (aq) (Sodium Hydroxide)* • 2 M H2SO4 (aq) (Sulfuric Acid)* • 3 M HCl (aq) (Hydrochloric Acid)* • Zinc* • Acetone • Filter Paper • 250mL Beaker • Flask • Filter Flask • Büchner funnel • Vacuum Valve • Triple Beam Scale *Amount to be determined- The amount will be determine later using stoichiometry using the mole to mole ratios of each equation.

  4. Procedure • Obtain 0.500g of copper wire weigh on a triple beam scale and placed in the bottom of a flask. • Use mole to mole conversion to determine amount of 6 M HNO3 (aq) and 6 M NaOH (aq). • Use gram to gram conversion to determine amount of 2M H2SO4 (aq) and zinc. • Pour 6 M HNO3 (aq) into the flask under a fume hood • After reaction takes place the reaction will be a light blue liquid and form Cu(NO3)2 (aq). • Place flask into ice bath, slowly add 6 M NaOH (aq) • Add Cu(NO3)2 (aq) until a solid forms at the bottom of the flask forming Cu(OH)2 (s). • Set up a filtration system , allow filtered solid to dry. Weigh solid and place solid back into flask.

  5. Procedure • Pour 2 M H2SO4 (aq) into flask. Swirl flask until solid dissolves forming Cu2(SO)4(aq). • Weigh out zinc on a triple beam scale and add to flask. Caution! Adding zinc will cause solution to be warm to the touch and bubble. Be cautious when handling! • Add 3 M HCl (aq) into the flask and swirl the flask. Repeat until solution is a transparent colorless solution. • Using the filtration system filter the solution and a solid should form. • Allow the solid to dry and rinse solid with acetone to remove any impurities. • Remove solid and place on a filter paper and weigh your solid on a triple beam scale. • Observe your solid, if any black copper is present remove it and reweigh your solid. • Use the percent yield equation to determine the amount of copper you recovered. • To see an example of the copper cycle lab go to: What is a Copper Cycle?

  6. Reactions • Solid copper reacts with aqueous nitric acid (HNO3 (aq)) Cu (s) + 4HNO3(aq) Cu(NO3)2(aq) + 2NO2 (g) + 2H2O (l) • Aqueous copper (II) nitrate reacts with aqueous sodium hydroxide (NaOH (aq)) Cu(NO3)2(aq) + 2NaOH (aq) Cu(OH)2(s) + 2NaNO3 (aq) • Solid copper (II) hydroxide reacts with aqueous sulfuric acid (H2SO4 (aq)) Cu(OH)2(s) + H2SO4 (aq) CuSO4(aq) + 2H2O (l) • Aqueous copper (II) sulfate reacts with solid zinc CuSO4(aq) + Zn (s) ZnSO4(aq) + Cu (s) • Solid zinc reacts with aqueous hydrochloric acid (HCl (aq)) Zn (s) + 2HCl (aq) ZnCl2(aq) + H2 (g)

  7. Results Formulas for reactions 1-2: Grams Cu X X X Reaction 1: 0.320 g Cu X X X 3.35 X 2 = 6.71 ≈ 7.00 mL HNO3 Reaction 2: 0.320 g Cu X X X 1.67 x 9 = 15.10 ≈ 15.00 mL NaOH Reaction 1 equation: Cu (s) + 4HNO3 (aq) → Cu(NO3)2 (aq) + 2NO2 (g) + 2H2O (l) Reaction 2 equation: Cu(NO3)2 (aq) + 2NaOH (aq) → Cu(OH)2 (s) + 2NaNO3 (aq)

  8. Results Zn (s) + 2HCl (aq) ZnCl2 (aq) + H2 (g) Formulas for reaction 3: Grams Cu(OH)2 X X X Reaction 3: 1.113 g Cu(OH)2 X X Reaction 3 equation: Cu(OH)2(s) + H2SO4 (aq) → CuSO4 (aq) + 2H2O (l)

  9. Results Formulas for reaction 4: Grams Cu(OH)2X X X Reaction 4: 1.113g Cu(OH)2 X X X 0.746 ≈ 0.700 g Zn Reaction 4 Equation: CuSO4(aq) + Zn (s) → ZnSO4 (aq) + Cu (s) Formula Percent Yield: ) X 100= X 100 = 60%

  10. How Much Sodium Bicarbonate is in the Mixture? • Materials: • (2) 250mL Beakers • (2) 25mL Cylinders • Approximately 1g of HCl (aq) • 1g of NaHCO3 (s) • 1g of “unknown” • Weighing paper • Triple Beam Balance Scale

  11. Trial of HCl • Measure out approximately 25mL HCl (aq) • Measure out approximately 1g of NaHCO3 (s) • Mix HCl (aq) and NaHCO3 (s) in a 250mL beaker. • Once reaction stops weigh the mixture. Repeat three times for accuracy.

  12. Formulas • The first three columns are determined by weighing the solutions in a 250mL beaker on a triple beam scale. • Mass of CO2: (Mass of NaCO3+ Mass of Acid) - Mass After Reaction • Theoretical Mass of CO2: Mass of NaCO3 = grams of CO2 • Percent Error: 100%

  13. Calculations • Trial 1: • Mass of CO2:(0.972 g+24.55 g)-24.54 g= 0.982 g CO2 • Theoretical Mass of CO2:0.972g NaCO3= 0.509 g CO2 • Percent Error: • Trial 2: • Mass of CO2:(0.966 g+ 24.50 g)-24.67 g= 0.806 g CO2 • Theoretical Mass of CO2:0.966g NaCO3 = 0.506 g CO2 • Percent Error: • Trial 3: • Mass of CO2:(01.00 g+ 24.51 g)-24.66 g= 0.840 g CO2 • Theoretical Mass of CO2:1.00g NaCO3 = 0.524 g CO2 • Percent Error:

  14. Trial of H2SO4 • Measure out approximately 14g H2SO4 (aq) • Measure out approximately 1g of NaHCO3 (s) • Mix H2SO4 (aq) and NaHCO3 (s) in a 250mL beaker. • Once reaction stops weigh the mixture. Repeat three times for accuracy.

  15. Calculations • Review Formulas • Trial 1: • Mass of CO2:(0.998 g+13.195 g)-13.294 g= 0.950 g CO2 • Theoretical Mass of CO2:0.998g NaCO3 = 0.518 g CO2 • Percent Error: • Trial 2: • Mass of CO2:(1.00 g+12.452 g)-12.410 g= 1.042 g CO2 • Theoretical Mass of CO2:1.00g NaCO3 = 0.524 g CO2 • Percent Error: • Trial 3: • Mass of CO2: (0.997 g+12.820 g)-12.480 g= 1.337 g CO2 • Theoretical Mass of CO2:0.997g NaCO3 = 0.522 g CO2 • Percent Error:

  16. Trial of “Unknown” • Measure out approximately 25mL HCl (aq) • Measure out approximately 1g of “unknown” • Mix HCl (aq) and “unknown” in a 250mL beaker. • Once reaction stops weigh the mixture. Repeat three times for accuracy.

  17. Formulas: • Mass of CO2: • (Mass of “Unknown”+ Mass of Acid) - Mass After Reaction • Mass of NaHCO3: • Percent Mass Composition: x100% For all trials: • Average mass of CO2:= 0.876g CO2 • Average mass of NaHCO3:= 0.979g NaHCO3

  18. Calculations: • Trial 1: • Mass of CO2:(1.00 g+24.23 g)-24.619 g= 0.611 g CO2 • Mass of NaHCO3:0.683 g NaHCO3 • Percent Mass Composition: X 100= 68.3% • Trial 2: • Mass of CO2: (1.00 g+24.09 g)-24.459 g= 0.631 g CO2 • Mass of NaHCO3:0.705 g NaHCO3 • Percent Mass Composition: X 100 = 70.5% • Trial 3: • Mass of CO2: (1.00 g+23.07 g)-24.414 g= 0.656 g CO2 • Mass of NaHCO3: 0.773 g NaHCO3 • Percent Mass Composition: X 100 = 77.3%

  19. Interested in Chemistry? • It does not take a chemists to do chemistry. • Following along with a procedure and using basic algebra anyone can do it and that includes YOU! • Just remember to follow the lab safety rules! • Think a chemistry major is not for you? • Do these experiments plus more by taking CHM 113 at ASU and meet a general course requirement! • Interestedin chemistry? Check out the Department of Chemistry and Biochemistry at ASU!

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