Question 1 Reaction 1:
CuO(s)→Cu(s)+12O2(g)ΔG°=155kJ/molrx n

A chemist wants to produce Cu(s) from a sample of pure CuO(s) according to reaction 1, represented by the equation above.

(a) Using the data in the following table, calculate the value of the standard entropy change, ΔS°, for the reaction.

Substance Absolute Entropy at298 K (JK−1mol−1)
Cu(s) 33
O2(g) 205
CuO(s) 43

Question 2
(b) Given that ΔG° for reaction 1 is positive (155kJ/molrxn), what must be true about the sign of ΔH° for the reaction? Justify your answer.

Question 3
The decomposition of CuO(s) into Cu(s) and O2(g) is not a thermodynamically favored reaction. However, to produce Cu(s) from CuO(s), the chemist decides to pass H2(g) gas over the CuO(s) as it is heated strongly, as represented below.

Reaction 2:
CuO(s)+H2(g)−→−−−− heat Cu(s)+H2O(g)

(c) Reaction 2 is what type of chemical reaction? Justify your answer.

Question 4
A third chemical reaction is represented below.

Reaction 3:
H2(g)+12O2(g)→H2O(g)ΔG°=−229kJ/molr xn

(d) Show how a combination of reaction 1 and reaction 3 can be used to produce reaction 2.

Question 5
(e) Determine the value of ΔG° for reaction 2.

The chemist takes the Cu(s) produced from reaction 2 and uses it to make an electrode in a galvanic cell, as shown in the following diagram.

The figure presents a diagram of a galvanic cell consisting of two solutions in beakers, two metal electrodes, a salt bridge, and a wire. The half-cell on the left shows a copper electrode partially submerged in a solution of 1.0 molar copper sulfate. The half-cell on the right shows a silver electrode partially submerged in a solution of 1.0 molar silver nitrate. A salt bridge connects the two solutions. A wire connects the copper electrode and the silver electrode, and an arrow indicates that the electron flow through the wire is from the copper to the silver.

Question 6
(f) Using the reduction half-reactions in the table below, write a balanced net-ionic equation representing the overall reaction that takes place as the cell operates.

Half-Reaction E° (volts)
Cu2+(aq)+2e−→Cu(s) 0.337
Ag+(aq)+e−→Ag(s) 0.800
0 / 10000 Word Limit
Question 7
(g) Determine the value of E° for the cell.

Question 8
(h) Determine the value of ΔG° for the cell reaction.