Experiment 5 Some Reactions of Copper

1. Experiment 5 Some Reactions of Copper

2. Goal To perform, observe and record observations regarding the chemical reactions of copper.

3. HNO3 Zn NaOH H2SO4 Heat Copper Reactions - Overview

4. Synthesis of Copper(II) Nitrate, Cu(NO3)2 HNO3 • Oxidation Reduction reaction • Copper is oxidized (loses electrons) – Oxidation number goes from 0 to +2 • Nitrogen is reduced (gains electrons) – Oxidation number goes from +5 to +4.

5. Synthesis of Copper(II) Hydroxide, Cu(OH)2 HNO3 NaOH

6. Synthesis of Copper(II) Hydroxide, Cu(OH)2 HNO3 NaOH • The first reaction is a neutralization reaction which generates heat (NaOH reacts with leftover HNO3) • The second reaction(copper) is a metathesis reaction • The nitrate and hydroxide groups are exchanged

7. Synthesis of Copper(II) oxide, CuO HNO3 NaOH Heat This is a decomposition reaction.

8. Synthesis of Copper(II) Sulfate, CuSO4 HNO3 NaOH H2SO4 Heat • While not obvious, this is a neutralization reaction (the products are a salt and water). • CuO is the base and H2SO4 is the acid. • It can also be classified as a metathesis reaction.

9. Synthesis of Copper HNO3 Zn NaOH H2SO4 Heat • The final reaction is a oxidation-reduction reaction. • Cu2+(aq) is reduced. Its oxidation number goes from +2 to 0 • Zn(s) is oxidized. It oxidation number goes from 0 to +2.

10. Synthesis of Copper HNO3 Zn NaOH H2SO4 Heat • There is a second competing reaction which occurs at the same time. • Zn is oxidized. Its oxidation number goes from 0 to +2 • H+ is reduced. Its oxidation number goes from +1 to 0

11. Technique - Centrifuge A centrifuge is a device that spins solid-liquid mixtures at high speeds in order to separate the mixture into two distinct layers. Centrifuges are cool. Take one for a spin…

12. Technique - Centrifuge • The centrifuge cover must be closed while the centrifuge is operating.

13. Technique - Centrifuge • The centrifuge cover must be closed while the centrifuge is operating. • The centrifuge must be kept balanced at all times. • Sample tubes must always be inserted in pairs, with each member of the pair containing equal volumes of liquid.

14. Technique - Centrifuge • The centrifuge cover must be closed while the centrifuge is operating. • The centrifuge must be kept balanced at all times. • Sample tubes must always be inserted in pairs, with each member of the pair containing equal volumes of liquid.

15. Technique - Centrifuge • The centrifuge cover must be closed while the centrifuge is operating. • The centrifuge must be kept balanced at all times. • Sample tubes must always be inserted in pairs, with each member of the pair containing equal volumes of liquid.

16. Technique - Centrifuge • The centrifuge cover must be closed while the centrifuge is operating. • The centrifuge must be kept balanced at all times. • Sample tubes must always be inserted in pairs, with each member of the pair containing equal volumes of liquid. • When sharing a centrifuge, be sure to label each tube or note the number on the rotor head. • Do not attempt to stop the centrifuge, let it spin down on its own.

17. Technique - Centrifuge

18. Copper(II) Nitrate, Cu(NO3)2 HNO3 Do this experiment in the hood, since NO2 is a noxious gas. Use only as much HNO3 as is necessary.

19. Copper(II) Hydroxide, Cu(OH)2 HNO3 NaOH Be sure to keep your sample cool. Mix the contents of the test tube. Test for completeness of reaction.

20. Copper(II) oxide, CuO HNO3 NaOH Heat Since water is formed in this reaction, the product will appear “soupy”.

21. Copper(II) Sulfate, CuSO4 HNO3 NaOH H2SO4 Heat Be sure that all the brown CuO in the test tube is allowed to react with the sulfuric acid

22. Copper HNO3 Zn NaOH H2SO4 Heat Keep the solution agitated to ensure that fresh Cu2+ is always in contact with the zinc.

23. Safety • 6M H2SO4 and concentrated HNO3 are corrosive. • It will blister the skin, and can damage books and clothing • Wash affected skin with water for 5 minutes. • Wash eyes for 10 minutes and call for medical attention. • 6M NaOH is corrosive. • It will burn the skin, and can seriously damage the eyes. • Wash affected skin with water for 5 minutes. • Wash eyes for 10 minutes and call for medical attention. • Nitrogen dioxide is a noxious (and toxic) gas, reactions that generate this gas should be performed in the fume hood. • The reaction between zinc and sulfuric acid generates H2 gas, which is flammable and can be explosive.

24. Waste Disposal Place recovered copper into the container marked: “Recovered Metals and Metal Ions” All other substances can be flushed down the sink with plenty of water.

25. Format • Even though two students share a drawer, each student does their own experiment.

26. Advising • Registration for Spring 2007 begins October 30, 2006 (note the change in date from what may be published in the guide) • Check in the main department office (of your major) to see who is your advisor. • Please keep in mind that the faculty member who advised you during orientation may not be your permanent advisor. • Do NOT wait until the last minute to get advised. • You will NOT be able to register until you have been advised and your advisor has lifted your “flag”.

27. Important Reminders - Prerequisites • In order to take CHEM 1212 and CHEM 1212L, you need to meet the following prerequisites: • MATH 1111 or MATH 1113 • CHEM 1211 • CHEM 1211L • In all courses, you MUST have a grade of “C” or better. • Even though the system may let you register, we will be checking the grades at the end of the semester to ensure that all students registered for CHEM 1212 and/or CHEM 1212L have good enough grades. • If you do not have the grades, you will not be allowed to remain in CHEM 1212 AND CHEM 1212L courses in Spring 2007.