# Electrochemistry NEET Questions With Answer Free pdf

The National Testing Agency (NTA) will conduct the National Eligibility cum Entrance Test (NEET)-UG for MBBS, BDS admissions. The exam date for NEET 2021 is August 1 and only two months are left for the national level medical entrance test.
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## ELECTRO CHEMISTRY

1. What is the ECE of Ag ?(Atomic weight= 108)108

Ans. ECE=108/ 96500 = 0.001119 gm/coulomb

1. Write the unit of resistivity.

Ans. ohm cm

1. 1 Faraday of electricity is coulomb.

Ans. 96500

1. During dis charging of lead storage battery which electrolyte is consumed ?

Ans. Sulphuric acid is consumed.

1. Write the relationship between cell potential and equilibrium constant.

Ans. Ecell= Ecell-(2.303R T/nF)Log Kç

1. How many moles of H, will be liberated when 2 faradays of electricity is passed through 0.1M H²SO⁴ solution ?

Ans. 1 faraday will produce = 1 gm equivalent
hydrogen
= ½mole hydrogen.
2 faradays electricity will produce = 1 mole
hydrogen
.

7.Write the Nernst equation for a half cell reaction. 0.059

Ans. E° cell= E log [M””]cell n
Where Cell = potential of the half cell.
E⁰cellFceStandard cell potential of the half cell
n= number of electrons involved in the half cell
reaction as represented in the chemical equation.
[M”= metal ion concentration in the solution.
The half cell reaction i
Mn±(aq)+ ne–→M

8.In galvanized iron, the iron is coated with a layer of____metal.

Ans. zinc

1. Name the chemical substance used for silver plating.

Ans. Potassium argento cyanide, K[Ag(CN),1

1. During electrolysis of molten calcium hydride H2 gas is liberated at

Ans. Anode

1. What is electrolytie cell ?
Ans. The device in which electrical energy is used for the redox reaction is called electrolytic cell or volt meter.
2. Write the electrolysis products of CuSO, solution
Ising Pt-electrode.

Ans. Cu-metal will be deposited at cathode and O2 gas at anode.

1. In the cell Zn/Zn²//Cu2±/Cu, electrons few from__ electrode to ___electrode.

Ans. Zn-electrode to Cu-electrode.

1. Two metals A and B have E R =-0.76V and E⁰RP
+0.80 V respectively. Which metal will displace H² from dilute H,SO,?

Ans. The metal with lower standard reduction
potential (A) will displace H²from dilute H²SO⁴

1. How many Faradays of charge are required to convert 1 mole Cr,02 to Cr*?

Ans. Cr²O²+ 14H +6e– >2Cr³+7H²0 i.e. 6 Faradays of charge is required for this reduction.

1. Define equivalent conductance of an electrolyte.

Ans. It is defined as the conducting power of all the 1ons produced from 1 gm equivalent of the electrolyte in solution.

1. What is the charge carried by 1 mole nitride ion?

Ans. Anitride ion (N) carries three unit -ve charge
1 mole nitride ion carries three mole electronic charge = 3 x 96500 =289500C

1. Write two factors influencing electrolytic conductance.

Ans. Temperature, concentration and nature of electrolyte.

19.Write two applications of electrolysis.

Ans. Electroplating. electrorefining of metals.

1. Define electrochemical equivalent.

Ans. It is defined as the mass of the substance liberated by the passage of 1 coulomb of electricity through the electrolyte.

1. What is the charge in coulomb carried by an oxide ion ?

Ans. oxide ion is O² So its charge 2x 1.6 x 10-1°C.

1. Which one of the following is a weak electrolyte? (NaCl, CH,-COOH, HCI)

Ans. CH,- COOH

1. Between 1 M CH,COOH and 0.1M CH,COOH, which has higher electrical conductivity ?

Ans. According to Ostwald’s dilution law the degree of dissociation of 0.1M CH³ C0OH is higher than 1 M CH³COOH. Therefore 0.1M CH³COOH solution has higher electrical conductance.

1. Why does the equivalent conductance of a strong electrolyte increase with increase in dilution ?

Ans. With increase in dilution, the interionicbattraction of a strong electro lyte decreases, so that ionic mobility increases. Hence the equivalent conductance increases.

1. Find the number of electrons present in 1 coulomb charge ?

Ans. 96500 C charge = 6-023 x 10²³ electrons.
1C charge=6-023x 102/96500 electrons
= 6-24x 10 electrons.

1. How much electric charge is required to oxidise 1 mole water to oxygen ?

Ans. H,O %0, +2H +2e

1. mole electrons are involved during oxidation of I mole water to oxygen.Quantity of electric charge = 2x 96500 =1.93×10 coulomb. Write the factors influencing electrode potertial of a metal.

Ans. Temperature, concentration of metal ion in solution and nature of the electrode

1. How does equivalent conductance of a weak electrolyte vary with dilution ?

Ans. With increase in dilution the equivalent conductance of a weak electrolyte increases.

1. Rewrite correctly the sentence- An electrolyte Conducts electricity due to movement of electrons.

Ans. An electrolyte conducts electricity due to movement of ions.

1. Write the Zn-CuSO, cell reacction.

Ans. Zn + Cu²→ Zn²(aq)+ Cu

1. What is strong electrolyte ? Give an example.

Ans. The electrolyte which is dissociated completely in aqucous solution is called as strong electrolyte. eg. NaCl, KCI etc.

1. While constructing a galvanic cell, the electrode with higher reduction potential is choosen as while the electrode with lower reduction potential is chosen as .
Ans. Cathode, dnode
2. Why does fused NaCl conduct electricity ?

Ans. Due to presence of free Nat and CF ions.

1. quantity of electricity will deposit 10.8 gm of ‘Ag’ at cathode from AgNO3 solution.

Ans. 9650 coulomb

1. The charge carried by 1 mole electron is equal to
Ans. 96500 coulomb or 1 Faraday
2. If a spoon to be electroplated with silver, would it be made as cathode or anode in the cell?

Ans. Cathode

1. How does specific conductance vary with dilution ?

Ans. Specific conductance decreases with increase in dilution.

1. What is the relationship between molar conductance and equivalent conductance for an electrolyte?

Ans= Am=Normality/molarity=n
Where Aeq equivalent conductance molarconductance
Am=molarconduction
n=acidity of a base/basicity of an acid/total valency
of metal atom of a salt.

1. The exact value of emf of a cell can be measured by means of

Ans. potentiometer

1. At infinite dilution the molar conductance of Na and So²⁴– ions are 50Nem mole and 160cm mole respectively. What will be the molar conductance of soidum sulphate at infinite dilution.

Ans. m(Na²SO³) =2^m (Na+)+m (SO⁴²–)

1. Find the charge in coulomb required for oxidation of 1 mole hydrogen proxide to oxygen.

Ans. H,O, 0,+ 2H’ +2e I mole hydrogen peroxide needs 2 mole electrons for oxidation = 2x 96500 1.93x 10 C

1. Give the relationship between chemical equivalent and electrochemical equivalent of an element ?

Ans. Electrochemical equivalent Chemical equivalent 96500

1. Between Li’ and Na* ion which has higher ionic conductance in molten state ?

Ans. Li ion has higher conductance than Na ion. Because due to small size of Li’ ion, its ionic mobility is more than Na+.

1. Define electrolyte and give an example.

Ans. The substance which conducts electricity. either in its molten state or in equeous solution is called as electrolyte. eg. NaC1² H²SO⁴, NaOH, etc.

1. Which substance is used for Cu-plating ?

Ans. CuSO, solution and dilute H,SO, is used for copper plating.

1. Define specific conductance of an electrolyte.

Ans. It is defined as the conducting power of all the 1ons present in Icc of a solution.

1. Arrange the following in increasing order of their conductance in their aqueous solution. (urea, NaCL2 CH³COOH)

Ans. The order is – Urea < CH³ – COOH< NaCl Urea nonelectrolyte. CH-COOH- weak electrolyte NaCl Strong electrolyte.

1. Why can’t CusO, solution be stored in an iron vessel?

Ans. As iron is more reactive than copper, so the former will displace copper from CuSO⁴ solution. Hence iron vessel will react with CuSO⁴ so can’t be used for storing CuSO⁴ solution.

1. For the zine electrode the standard oxidaition potential is +0.76V. Then what is its stand reduction potential ?

Ans.-0.76 V

1. Why can’t Cu’ displace Zn’ from ZnSo⁴ solution ?

Ans. Because ‘Cu lies below Zn in the electro chemical series and it is less reactive than Zn.

1. Why can’t “Cu’ displace H, gas from dilute acids?

Ans. ‘Cu lies below hydrogen in the electro chemical series. So it can’t displace H² from dilute acids,

1. Define molar conductance.

Ans. It is the conducting power of all the ions produced from 1 mole of the electrolyte in solution.

1. What is the unit of equivalent Conductance ?

Ans. ohm–¹ cm² g equivalent–¹

1. At which condition of AG a cell will function ?

Ans. When AG = -ve, than a cell will function.

1. If same quantity of electricity is passed through ZnSO⁴ solution and AgNO³ solution, which metal will be deposited in more quantity?

Ans. Silver will be deposited in more quantity.

1. What are the electrolytic products of aqueous NaCl2?

Ans. H² gas at cathode and Cl² gas at anode

1. What is galvanic cell ?

Ans. The device in which electrical energy is produced as a result of redox reaction is called as gavanic cell or voltaic cell.

1. In an electrolytic cell oxidation occurs at……and reduction at

Ans. anode, cathode

1. Suggest two materials other than H, that can be used as fuels in fuel cell.

Ans. Methane and methanol.