The Chemical Reactions of Copper and Percent Recovery
Using the information from the YouTube video and the Experiment Information Word document, complete Table 1 as if you performed the experiment.
Table 1: Results of Copper Cycle:
Action Taken: Results
Determine the Initial Mass of the copper metal 0.840 g
Determine the mass of the empty evaporating dish 80.769 g
Determine the mass of the empty evaporating dish and recovered copper 81.739 g
Determine the Mass of Recovered Copper =81.739 g – 80.769 g = 0.97 g
Determine the Percent Recovery of Copper 115.5%
Calculations: Show all work to receive credit
Determined the mass of recovered copper:
= Initial mass of Cu – Recovered mass of Cu
The mass of recovered copper = 81.739g – 80.769 g = 0.97000 g
Determined the percent recovery of copper:
% recovery = (Mass of Cu recovered/mass of Cu initially) x 100
= 0.97g/0.840g x 100 = 115.5%
To complete Table 2:
List all products formed for each reaction and balance the equation. Include states of matter, i.e. (s), (l), (g), or (aq).
List the reaction type for each reaction. Options are Decomposition, Single Replacement, Double Replacement, Redox Reaction
Match the following photo observations to the reaction step.
Some steps may have more than one photo.
Do not use a photo more than one time.
Some photos might not be used.
Copy and paste the photo into the last column of Table 2 for observations.
Double replacement reaction
Thermal decomposition reaction
Oxidation reaction
Single replacement reaction step
Table 2: Observations from Copper Cycle Lab
Reaction Product(s) Formed Type of Reaction Observations
Cu(s) + 4 HNO3(aq) → Cu(NO3)2 (aq) + 2NO2(g) + 2H2O(l) Oxidation reaction A clear and transparent blue solution
Cu(NO3)2 (aq) + 2NaOH(aq) → Cu(OH)2(s) + 2NaNO3(aq) Double replacement reaction A light blue solid is formed
___ Cu(OH)2(s) + heat → CuO (s) _ H2O (l) Thermal decomposition reaction A black and insoluble solid is formed
___ CuO(s) + ___ H2SO4(aq) → CuSO4(aq) + H2O(l) Neutralization reaction A sky blue solution is formed
___ CuSO4(aq) + ___Zn(s) → ZnSO4 (aq) + Cu (s) Single replacement reaction A reddish brown solid is formed
The introduction and conclusion sections must be typed up as a word document using double spacing. Do not use personal pronouns. When writing in a sentence, you must name the chemical(s), do not use chemical formula.
Introduction
The main aim of this experiment is to demonstrate the cycle of reactions that involve copper by examining the transformation of copper via a series of reactions and ultimately recovering the solid copper. This particular lab work aids in observing different types of chemical reactions and relating observations to these particular reactions in order to reinforce the analogy of atoms preservation in the chemical reactions. The quantitative techniques will also be practiced by trying to recover the original Cu and calculating the percentage recovery. Various reactions occur in this experiment. Single replacement reactions entails displacement of one chemical moiety by another whereby a more reactive element displaces the less reactive one from the compound (Saunders, 2008). Double displacement reaction is a metathesis reaction where two species are displaced. Redox reactions entails the transfer of electrons from one reactant to the other. Lastly, the decomposition reaction involves the breakdown of the compound into two or more simpler substances (Murphy, Gwinn, & Dix, 2006).
Conclusion
In the dissolution of copper, nitric acid oxidizes Cu metal to Cu2+ ions forming a blue solution and a dense red-brown NO2 gas. This particular reaction is an oxidation reaction where the Cu elements increase in charge and the blue solution indicates the presence of Cu ions. In the second reaction, NaOH is a strong base and thus neutralizes copper ii nitrate into copper ii hydroxide that appears a precipitate of a light blue solid. The Cu(OH)2 is then converted and is thermally decomposed into CuO in step 3. In this step, heating the hydroxide drives off the water from the solid resulting in an oxide. In the fourth part, an acid base reaction is performed between CuO and sulphuric acid resulting in a sulphate of copper that is then reduced by zinc into Cu metal which is reddish brown in color.
In the above experiment, two reactions form the aqueous product of copper. In the dissolution of Cu metal in nitric acid, an aqueous product of Cu(NO3)2 is formed from the reaction: Cu(s) + 4 HNO3(aq) → Cu(NO3)2 (aq) + 2NO2 (g) + 2H2O (l). Similarly, in the dissolution of CuO in sulfuric acid, an aqueous CuSO4 product is produced based on the equation below: CuO(s) + H2SO4(aq) → CuSO4(aq) + H2O(l).
In the step where the blue precipitate changes to the black solid, the heat applied to the Cu(OH)2 causes the black CuO to form. Heating the hydroxide drives off the water from the solid resulting in the oxide. The resulting compound is thus black in color. The black precipitate is CuO.
The reaction taking place between CuSO4(aq) and Zn(s) is indicated by the colour change from a sky blue solution to a reddish brown solid. This is an indication of a reduction of Cu2+ ions to form copper that is reddish brown. This particular cues aid in knowing the reaction has gone to completion when the blue color completely