Tag: patterns and properties of metals

Quizzes (5) Questions (65)

Questions Related to patterns and properties of metals

Multiple choice electrical cells patterns and properties of metals chemistry

Which of the following statement is incorrect about electrochemical cell?

  1. Electrons are released at anode

  2. Chemical energy is converted into electrical energy

  3. Salt bridge maintains the electrical neutrality of the electrilytes

  4. Cell can work indefinitely
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Electrochemical cells are designed to operate until the chemical reactants are consumed or the cell reaches equilibrium. They cannot work indefinitely, as that would violate the laws of thermodynamics.

Multiple choice electrical cells patterns and properties of metals chemistry

The following electrochemical cell is taken $Cu| Cu^{2+}(aq)|| Ag^{+}(aq))| Ag$ and has emf $E _{r}>0$ by which of the following actions $E _{1}$ increases?

  1. Adding $NH _{3}$ to the cathodic chamber
  2. Adding $HCl$ to the cathodic chamber
  3. Adding $AgNO _{3}$ to the anodic chamber
  4. Adding $NH _{3}$ to the anodic chamber
Reveal answer Fill a bubble to check yourself
D Correct answer
Multiple choice electrical cells patterns and properties of metals chemistry

Find out ${E} _{cell}$ of following electrochemical cell (${E} _{{Br} _{2}/{Br}^{-}}=1.09V$)
$Pt(s)\mid {Br} _{2}(l)\mid{Br}^{-}(0.01M)\mid\mid{H}^{+}(0.01M)\mid{H} _{2}(g)(1bar)\mid Pt(s)$

  1. $-1.32V$
  2. $+1.09V$
  3. $-2.15V$
  4. $-1.92V$
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice electrical cells patterns and properties of metals chemistry

The following electrochemical cell has been set up: $Pt(s)|Fe^{3+}, Fe^{2+}(a=1)||Ce^{4+}, Ce^{3+}(a=1)|Pt(s); E^{\circ}(Fe^{3+}|Fe^{2+})= 0.77V$; $E^{\circ}(Ce^{4+}|Ce^{3+})= 1.61V$. If an ammeter is connected between the two platinum electrodes, predict the direction of flow of current. Will the current increase or decrease with time?

  1. Ce electrode to Fe electrode, decrease

  2. Ce electrode to Fe electrode, increase

  3. Fe electrode to Ce electrode, decrease

  4. Fe electrode to Ce electrode, increase
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The cell potential is E_cell = E_cathode - E_anode = 1.61 - 0.77 = 0.84V. Since E_cell > 0, the reaction is spontaneous. Electrons flow from the anode (Fe) to the cathode (Ce). Current flows from the Ce electrode to the Fe electrode. As the reaction proceeds, the concentrations change, moving toward equilibrium, which causes the voltage and current to decrease.

Multiple choice electrical cells patterns and properties of metals chemistry

After some time, the voltage of an electrochemical cell becomes zero. This is because ____________________.

  1. their electrode potential becomes zero.

  2. their reduction potential become equal but have opposite sign

  3. their reduction potential become equal and have the same sign.

  4. the ions of the electrolyte in the salt bridge stop moving.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When a cell reaches equilibrium, the reaction quotient Q equals the equilibrium constant K. At this point, the cell potential E becomes zero, which corresponds to the point where the reduction potentials of the two half-cells are equal.

Multiple choice electrical cells patterns and properties of metals chemistry

Which one of the following statements is incorrect regarding an electrochemical cell?

  1. The electrode on which oxidation takes place is called anode.

  2. Anode is the negative pole.

  3. The direction of the current is same as that of the direction of flow of electrons.

  4. The flow of current is partly due to flow of electrons and partly due to flow of ions.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

By convention, the direction of conventional current is defined as the opposite of the direction of electron flow. Electrons flow from anode to cathode, so current flows from cathode to anode.

Multiple choice electrical cells patterns and properties of metals chemistry

The first electro-chemical was invented by:

  1. Luigi Galvani.

  2. Alessandro Volta.

  3. Deniel.

  4. Lechanche
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The first electrochemical cell was invented by Luigi Galvani in 1791. It was greatly improved by Alessandro Volta in the years of 1800.

Multiple choice electrical cells patterns and properties of metals chemistry

Statement $1$: In an electrolytic cell, the anode becomes positive and the cathode becomes negative.
Statement $2$: Anions migrate to the anode and cations migrate to the cathode.

  1. Statement $1$ and Statement $2$ are correct and Statement 2 is the correct explanation of Statement $1$.
  2. Both the Statement $1$ and Statement $2$ are correct, but Statement $2$ is NOT the correct explanation of Statement $1$.
  3. Statement $1$ is correct, but Statement $2$ is not correct.
  4. Statement $1$ is not correct, but Statement $2$ is correct.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
|  In electrolytic cell |  In galvanic cell | | --- | --- | |  Anode $=+ve$ |  Anode $=-ve$ | |  Cathode $=-ve$ |  Cathode $=+ve$ |
Anions migrate to anode in electrolytic cell 
Cations migrate to cathode in electrolytic cell 

Multiple choice electrical cells patterns and properties of metals chemistry

The apparatus in which electrical energy is converted into chemical energy is known as:

  1. voltameter

  2. coulometer

  3. both (A) and (B)

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The apparatus in which electrical energy is converted into chemical energy is known as voltameter or coulometer.
Ag or Cu voltameters or coulemeters are used to measure the total charge passed through solution in terms of mass of Ag or Cu deposited there on voltameter or coulometer cathode.

Multiple choice electrical cells patterns and properties of metals chemistry

Consider a spontaneous electrochemical cell containing $Cd, Cd^{2+}, Ag^{+}$, and $Ag$.
The reduction potential of $Cd$ is $-0.403\ V$ and $Ag$ is $0.799\ V$.

What is the balanced equation for the reaction that is occurring, and what is the electrochemical cell voltage?

  1. $Ag^{+} + Cd \rightarrow Cd^{2+} + Ag; 1.19\ V$
  2. $2Ag^{+} + Cd \rightarrow Cd^{2+} + 2Ag; 1.20\ V$
  3. $Ag^{+} + Cd \rightarrow Cd^{2+} + Ag^{+}; 0.40\ V$
  4. $2Ag^{+} + Cd \rightarrow Cd^{2+} + 2Ag; 2,30\ V$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
We have,
$E^0$ of Cd = -0.403V ( oxidation will favour)
$E^0$ of  Ag = 0.799V (reduction will favour)

So, the net reaction becomes:

$2 Ag^+ + Cd \rightarrow Cd^{2+} + 2Ag$

and $E^0 _{cell}  = 0.799 - (-0.403) = 1.202 V$