What will be the $ E_{cell} $ for the given cell ?
$ Zn\left|Zn^{2+}\left(0.1\,M\right)\right|\left|Cu^{2+}\left(0.01\,M\right)\right|Cu $
Given : $ E^{\circ}_{Zn^{2+}Zn}=0.76\,V $ and $ E^{\circ}_{Cu^{2+}Cu}=0.34\,V $ .
Also predict whether the reaction is spontaneous or non-spontaneous.
\(Zn\left|Zn^{2+}\left(0.1\,M\right)\right|\left|Cu^{2+}\left(0.01 M\right)\right|Cu\) \(E_{\text{cell}}=E_{\text{cell}}^{\circ}-\frac{0.0591}{n} log \frac{\left[Zn^{2+}\right]}{\left[Cu^{2+}\right]}\) \(E_{\text{cell}}^{\circ}=E^{\circ}_{\left(Cu^{2+}Cu\right)}-E^{\circ}_{\left(Zn^{2+}Zn\right)}\) \(=0.34-\left(-0.76\right)=1.10\,V\) \(E_{\text{cell}}=1.10-\frac{0.0591}{2} log \frac{0.1}{0.01}\) \(E_{\text{cell}}=1.10-0.03=1.07\) As \(E_{\text{cell}}\) is positive, the reaction is spontaneous
A spontaneous process in spontaneity is an irreversible one that takes place without the need of outside energy or agents. This process is independent of the reaction rate's kinetics, hence it can go slowly or swiftly.
A spontaneous reaction is a type of reaction that takes place naturally and uninhibited under specific conditions.
The majority of the time, a spontaneous reaction can be completed on its own.
Simply because a reaction is spontaneous doesn't mean that it happened that way.
Salt dissolves in water, fruit ripens spontaneously without any energy or assistance, and ice melts naturally.
One of the crucial factors that determines the spontaneity of any process in a chemical equation is total entropy.
Entropy is a measure of a system's disorder or unpredictability. German scientist Rudolf Clausius originated the idea of entropy in the year 1850.
Entropy is a state function that is dependent on the system's state but not on the route taken.
Most chemical processes may be divided into closed and open systems, and we can state that along with a change in entropy, there is also a change in enthalpy.
Exothermic or endothermic reactions can occur involuntarily. Another way to put it is that spontaneity need not be connected to a process's delta (H) enthalpy change, which stands for the change in enthalpy.
The unpredictability of the chemical equation, which also affects molecular movements, changes as enthalpy changes.
The spontaneity of such a process is not just due to entropy change.
Thus, the process of spontaneity has been explained using the Gibbs energy change.
An electrochemical cell is a device that is used to create electrical energy through the chemical reactions which are involved in it. The electrical energy supplied to electrochemical cells is used to smooth the chemical reactions. In the electrochemical cell, the involved devices have the ability to convert the chemical energy to electrical energy or vice-versa.
Classification of Electrochemical Cell:
Cathode
Denoted by a positive sign since electrons are consumed here
A reduction reaction occurs in the cathode of an electrochemical cell
Electrons move into the cathode
Anode
Denoted by a negative sign since electrons are liberated here
An oxidation reaction occurs here
Electrons move out of the anode
Types of Electrochemical Cells:
Galvanic cells (also known as Voltaic cells)
Chemical energy is transformed into electrical energy.
The redox reactions are spontaneous in nature.
The anode is negatively charged and the cathode is positively charged.
The electrons originate from the species that undergo oxidation.
Electrolytic cells
Electrical energy is transformed into chemical energy.
The redox reactions are non-spontaneous.
These cells are positively charged anode and negatively charged cathode.
