Question

A hypothetical cell electrochemical cell is: \[A|{A^ + }\left( {xM} \right)\parallel {B^ + }\left( {yM} \right)|B\] . The emf measured is \[ + 0.20V\] . The cell reaction is:
A.Cannot be predicted
B.\[A + {B^ + } \to {A^ + } + B\]
C.\[{A^ + } + B \to A + {B^ + }\]
D.\[{A^ + } + {e^ - } \to A;{B^ + } + {e^ - } \to B\]

Answer 1

Hint: An electrochemical cell is a device that converts chemical energy to electrical energy from chemical reactions. An electrochemical cell can be represented as anode separated by cathode. The salt bridge is a two-vertical line. Anode is written at the left side of the salt bridge and cathode is written at the right side of the salt bridge.

Complete answer:
An electrochemical cell is a device that converts chemical energy to electrical energy. There are two types of electrochemical cells. Voltaic cells or galvanic cells and electrolytic cells. The electrical energy can be generated from chemical reactions.
The electrochemical can be written as an anodic compartment at the left side followed by two vertical lines which can be known as a salt bridge and followed by a cathodic compartment.
Anodic compartment is the place where oxidation takes place and the cathodic compartment is the place where reduction takes place.
In this electrochemical cell, A undergoes oxidation and forms \[{A^ + }\], whereas \[{B^ + }\] undergoes reduction and forms B.
Anodic compartment: \[A \to {A^ + }\]
Cathodic compartment: \[{B^ + } \to B\]
Thus, the cell reaction is \[A + {B^ + } \to {A^ + } + B\]

Option B is the correct one.

Note:
At anodic compartment oxidation takes place as anode is a positive electrode. At cathodic compartment reduction takes place as cathode is a negative electrode. Oxidation can be defined as the loss of electrons and the reduction can be defined as gain of electrons.