CHEM120L Study Guide - Final Guide: Copper(Ii) Oxide, Vacuum Flask, Purified Water

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pearspider897

16 Oct 2011

School

University of Waterloo

Department

Chemistry

Course

CHEM120L

Professor

Sue Stathopulos

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Document Summary

Experiment #1 the chemistry of copper compounds. Know the equations of the reactions involved: Part 1 synthesis of copper (ii) nitrate and copper (ii) hydroxide. Put solid copper wire into a 250ml beaker and add 10ml of hno3 solution into the beaker under the fume hood. The reaction of cu with nitric acid (hno3) The copper ions were dissolved into the nitric acid and formed a blue solution. The solution began to fizz, showing the release of gases (no2 and h2o) nitric dioxide and water vapour. The solution began orange-green with many precipitates (cu(s)) and the final solution was clear blue. (cuno3(aq)) After dissolution is complete dilute with 25ml deionized water, then add 25ml of 20% Cu(no3)2(aq) + 2naoh(aq) cu(oh)2(s) + 2nano3(aq) + heat. The nitrate ions are displaced by the hydroxide ions, forming copper (ii) hydroxide. After naoh was added, the solution became hotter (exothermic!) and many black precipitates formed.

Related Questions

Iâve attached the lab procedures

Could I get some help with the questions please

Weigh boat is 2.20g

Weigh boat + copper is 2.43g

D) Hedung &f thÃ© precipitate in water decomposes the O)2 into CuO, a black solid (Rxn 3). Sulfuric acid is then added to dissolve the copper oxide, forming a light blue solution of Cu(l) ions (Rxn 4). Finally, zinc metal participates a redox reaction with both the copper ions (Rxn 5a) and the excess sulfuric acid (Rxn 5b) to form solid copper metal and evolve hydrogen gas. Using the initial mass copper and the mass of recovered copper after Rxn 5 is complete, the percent recovered fronm this cycle of copper reactions can be calculated using the equation: % Recovered (Final Mass of Copper/initial Mass of Copper)x100 This experiment is based on the manuscript: https:/www.apsu.edufiles/chemistry/COPPER CYCLE $10.pdf Aithough it doesn't show exactly what you will be doing in the lab today, the following video will give you a general idea of what to expect from this lab https://www.youtube.com/watch?v tyne4AFOVY ur Dissolution of Copper Preparation of Copper (Il) nitrate Obtain a sample of copper wire or turnings that weighs between 0.25 to 0.35 grams and place in a 250 mL beaker. Record the actual mass of copper used in your notebook 2. Obtain 4.0 ml of concentrated nitric acid from your instructor and IN THE FUME copper. Remember you need special gloves for this HOOD add it drop wise to the 3. Heat the beaker gently-but NOT to boiling-under the hood using a hot plate until the copper has completely dissolved and no orange gas is being released. If the liquid evaporates ask your instructor to add additional 2 mililiters of nitric acid into your sample and lower the temperature. BE PATIENCE as this is the slowest step of this series of reactions 4. After the copper is completely dissolved slowly add 15.0 mL of distilled water to the beaker and swirl. After adding water, the solution is safe to handle without special gloves, but you still must use regular nitrile gloves. You should see a blue solution that contains copper (I) nitrate. Preparation of Copper (II) Hydroxide 5. Place about 5 mL of 4 M NaOH in a small disposable test tube. Add the NaOH with a dropper to the solution containing the dissolved copper ions until a precipitate remains in the solution. What color is the new precipitate? Write it in your notebook) 6. Once the copper hydroxide has formed allow it to settle. 43

1.When aqueous solutions of ammonium phosphate and copper(II) nitrate are combined, solid copper(II) phosphate and a solution of ammonium nitrate are formed. The net ionic equation for this reaction is:
(Use the solubility rules provided in the OWL Preparation Page to determine the solubility of compounds.)

2. When aqueous solutions of potassium hypochlorite and nitric acid are mixed, an aqueous solution of potassium nitrate and hypochlorous acid results. Write the net ionic equation for the reaction.
(Use the solubility rules provided in the OWL Preparation Page to determine the solubility of compounds.)

Use H⁺ for the hydronium ion

3. Write a net ionic equation to show that nitric acid, HNO₃, behaves as an acid in water.

4. Write a net ionic equation to show that hydrofluoric acid , HF , behaves as an acid in water.

5. Write a net ionic equation to show why solid barium hydroxide, Ba(OH)₂ (s), forms a basic solution when it dissolves in water.

CHEM120L Study Guide - Final Guide: Copper(Ii) Oxide, Vacuum Flask, Purified Water

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