Answer : The correct option is, +91 kJ/mole
Solution :
The balanced cell reaction will be,

Here copper (Cu) undergoes oxidation by loss of electrons, thus act as anode. Lead (Pb) undergoes reduction by gain of electrons and thus act as cathode.
First we have to calculate the standard electrode potential of the cell.
![E^0_{[Pb^{2+}/Pb]}=-0.13V](https://tex.z-dn.net/?f=E%5E0_%7B%5BPb%5E%7B2%2B%7D%2FPb%5D%7D%3D-0.13V)
![E^0_{[Cu^{2+}/Cu]}=+0.34V](https://tex.z-dn.net/?f=E%5E0_%7B%5BCu%5E%7B2%2B%7D%2FCu%5D%7D%3D%2B0.34V)

![E^0_{cell}=E^0_{[Pb^{2+}/Pb]}-E^0_{[Cu^{2+}/Cu]}](https://tex.z-dn.net/?f=E%5E0_%7Bcell%7D%3DE%5E0_%7B%5BPb%5E%7B2%2B%7D%2FPb%5D%7D-E%5E0_%7B%5BCu%5E%7B2%2B%7D%2FCu%5D%7D)

Now we have to calculate the standard Gibbs free energy.
Formula used :

where,
= standard Gibbs free energy = ?
n = number of electrons = 2
F = Faraday constant = 96500 C/mole
= standard e.m.f of cell = -0.47 V
Now put all the given values in this formula, we get the Gibbs free energy.

Therefore, the standard Gibbs free energy is +91 kJ/mole
Answer:
a) 231.9 °C
b) 100% Sn
c) 327.5 °C
d) 100% Pb
Explanation:
This is a mixture of two solids with different fusion point:


<u>Given that Sn has a lower fusion temperature it will start to melt first at that temperature. </u>
So the first liquid phase forms at 231.9 °C and because Pb starts melting at a higher temperature, that phase's composition will be 100% Sn.
The mixture will be completely melted when you are a the higher melting temperature of all components (in this case Pb), so it will all in liquid phase at 327.5 °C.
At that temperature all Sn was already in liquid state and, therefore, the last solid's composition will be 100% Pb.
Answer:
A. a system that can be affected by the outside environment, by an exchange of matter or energy
The cubic unit cell this metal crystallize as is BCC structure .
<h3>
What is unit cell ?</h3>
The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell.
The unit cell consists of lattice points that represent the locations of atoms or ions.
The entire structure then consists of this unit cell repeating in three dimensions

n= 2
Hence our assumption was correct
It is a BCC structure .
Therefore the cubic unit cell this metal crystallize as is BCC structure .
To know more about unit cell
brainly.com/question/13110055
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Answer:
Chemical
Explanation:
The change was chemical, because it can no longer be returned to the original form. You cannot get back the bubbles or fizz from the air.