Chemical Reactions of Copper and Percent Yield Quiz

First Reaction

solid copper reacts with aqueous nitric acid to produce aqueous copper nitrate, nitrite gas, and water

solid copper reacts with aqueous nitric acid to produce aqueous copper nitrate, nitrite gas, and water

Cu(s) + 4HNO₃(aq) → Cu(NO₃)₂(aq) + 2NO₂(g) + 2H₂O(l)

What is the first reaction clasify as?

Redox

Second Reaction

aqueous copper nitrate reacts with aqueous sodium hydroxide to form solid copper hydroxide and aqueous sodium nitrate

aqueous copper nitrate reacts with aqueous sodium hydroxide to form solid copper hydroxide and aqueous sodium nitrate

Cu(NO₃)₂(aq) + 2NaOH (aq) → Cu(OH)₂ (aq) + 2NaNO₃(aq)

What does the second reaction classify as?

metathesis

Third Reaction

aqueous copper hydroxide heats into solid copper oxide and gaseous water

Cu(OH)2 (aq) → CuO (s) + H2O (g)

What is the third reaction classified as?

dehydration (decomposition)

Fourth Reaction

solid copper oxide reacts with aqueous sulfuric acid to produce aqueous copper sulfate and water

solid copper oxide reacts with aqueous sulfuric acid to produce aqueous copper sulfate and water

CuO(s) + H₂SO₄(aq) → CuSO₄(aq) + H₂O(l)

What is the fourth reaction classified as?

metathesis

Fifth Reaction

aqueous copper sulfate reacts solid zinc to produce aqueous zinc sulfate and solid copper

aqueous copper sulfate reacts solid zinc to produce aqueous zinc sulfate and solid copper

CuSO₄(aq) + Zn(s) → ZnSO₄(aq) + Cu(s)

What is the fifth reaction classified as?

Redox

Why was the copper washed at the end of the experiment?

to remove any excess salt of ZnSO4

In the reaction, Cu(s) + 4HNO₃(aq) → Cu(NO₃)₂(aq) + 2NO₂(g) + 2H₂O(l), what is oxidized, reduced, the oxidizing agent, and the reducing agent? 

oxidized- copper

reduced- nitrogen

oxidizing agent- nitrogen

reducing agent- copper

In the reaction, CuSO₄(aq) + Zn(s) → ZnSO₄(aq) + Cu(s), what is oxidized, reduced, the oxidizing agent, and the reducing agent? 

oxidized- zinc

reduced- copper

oxidizing agent- copper

reducing agent- zinc

Does oxidation occur in metathesis reactions?

no because there is no change in oxidation number of metathesis’ atoms

Does oxidation occur in dehydration reactions?

no because the addition or removal of water does not involve an oxidation or reduction reaction

What is the net ionic equation of the first reaction?

Cu(s) + 4H+(aq) + 4NO3- (aq)→ Cu+2 (aq) + (NO3)2- (aq) + 2NO2(g) + 2H2O (l)

What is the net ionic equation of the second reaction?

Cu+2 (aq) + OH- (aq) →Cu(OH)2 (s)

What is the net ionic equation of the third reaction?

Cu(OH)2 (s) → CuO(s) + H2O(s)

What is the net ionic equation of the fourth reaction?

CuO(s) + 2H+(aq) → Cu+2 (aq) + H2O(l)

What is the net ionic equation of the fifth equation?

Cu+2 (aq) + Zn(s) → Zn+2 (aq) + Cu(s)

Decantation

separating insoluble solids from liquids by pouring out the liquid while keeping the solids inside the container

Filtration

the solution passes through hte filter paper and is collected in a flask; solid collected in filter paper

extraction

transference of compound (s) from a solid or liquid into a different solvent or phase

First reaction, Cu(s) + 4HNO₃(aq)

1. added HNO3 to the beaker containing copper

2. it reacted to produce nitrate gas which was captured by the fume hood

   1. turned green, sizzled, orange smoke

3. then added 100mL of water to dilute the copper nitrate

4. ended up bluish green

Second reaction, Cu(NO₃)₂(aq) + 2NaOH (aq)

1. sodium hydroxide is added to copper nitrate

   1. turns clear blue into foggy lighter blue

   2. top layer is clear, bottom layer is cloudish looking texture (cloudish, dark grey)

2. produces solid copper hydroxide (grey cloudy stuff)

3. produces sodium nitrate (blue liquid)

Third Reaction, Cu(OH)2 (aq)

1. let black copper hydroxide settle before decanting

2. add 200mL of hot water to produce copper oxide

3. decant again to remove the water

4. black cloudy stuff is left

Fourth Reaction, CuO(s) + H₂SO₄(aq)

1. sulfuric acid is added to copper oxide

   1. turns blue and clear

2. produces copper sulfate and water in a solution

Fifth Reaction, CuSO₄(aq) + Zn(s)

1. zinc is added to the solution of water and copper sulfate under the fume hood

   1. bubbles; copper turns red

2. zinc is added and mixed until the solution is colorless with red copper at the bottom

3. then once here is no gas anymore, decant the solution

4. wash the copper with water and decant

   1. repeat twice to ensure that only copper is left

5. then let the copper air dry or heat the copper until it is dry

6. solid copper and zinc sulfate is produced

Reactants

solid copper, aqueous nitric acid, aqueous copper nitrate, aqueous sodium hydroxide, solid copper hydroxide, solid copper oxide, aqueous sulfuric acid, aqueous copper sulfate, solid zinc

Products

aqueous copper nitrate, gaseous nitrite, liquid water, solid copper hydroxide, aqueous sodium nitrate, solid copper oxide, gaseous water, aqueous copper sulfate, aqueous zinc sulfate, solid copper

Limiting Reactant

calculate the amount of product produced from each reaction; the reactant that produces the least amount is the limiting reactant; use grams, moles, and mole ratio to calculate; copper is the limiting reactant

% Yield

actual yield/ theoretical yield x 100%

What is the difference between filtration and decantation? Use technical terminology in your response. 

When filtration is used, liquid flows into a medium through which solids are unable to pass; decantation separates liquids from solids by slowly and carefully pouring the liquid from the container

Give two classifications for the HNO₃ used in the lab.

• a strong acid

• reactant

Give two classifications for the NaOH used in the lab.

• strong base

• reactant

Copper

Cu (s); red solid; insoluble; reactant and product

Copper nitrate

Cu(NO3)2 (aq); blue-green clear liquid; soluble; product and reactant

copper hydroxide

Cu(OH)2; solid; black cloudy, fluffy; insoluble; product and reactant

copper oxide

CuO; solid; black cloudy stuff; insoluble; product and reactant

copper sulfate

CuSO4; aqueous; blue and clear; soluble reactant and product

How did you know that the metathesis reactions went to completion?

there was a component that was removed from the solution; a solid (Cu(OH)2) from the 2 second reaction and water from the fourth reaction

What salts could remain on the copper retrieved in the last step if proper washing was not done in each of the previous steps that required washing the precipitate?

sodium nitrate and zinc sulfate

Which salt should have been removed in each of the steps that required you to wash the product?

sodium nitrate should be removed in reaction 3 if not already removed; zinc sulfate would have been removed after reaction 5

What effect, if any, would adding less than 2.00 g of Zn have on the copper produced by the final reaction of the lab, CuSO₄(aq) + Zn(s) → ZnSO₄(aq) + Cu(s)?

there would be less copper removed from the copper sulfate compound if there was less grams of zinc added

Why are measurements of a liquid more accurate when made using a graduated cylinder that when they are made using a beaker?

graduated cylinders are designed for accurate measurements of liquids with a much smaller error than beakers; has permanently marked incremental graduatins incorporated in the clear cylinder

What is the limiting reactant in the final reaction of the lab, CuSO₄(aq) + Zn(s) → ZnSO₄(aq) + Cu(s), when 2.00 g of Zn reacts with 20mL of 2.0 M CuSO₄(aq)? Show all math to support your answer.

Zinc is the limiting regeant

Explain how to prepare 1.00L of a 3.0M H₂SO₄(aq) from a concentrated solution of the acid that is 18.0 M.

• add .16667 L of 18.0 M H2SO4 to a beaker

• then add water until there is 1L of solution