Electrochemistry Questions and Answers

i ker 1 0 25 DP BP 26 a 3b C 2a b 2x0 1671 0 25 3 0167 1 0 142 0 5 0 167 xample 7 44 One mole of N O g at 100 K is kept in a sed container at 1 0 atm pressure It is heated to 400 K here 30 by mass of N O g decomposes to NO 2 The sultant pressure will he

Each question carries 8 marks 6 A What is galvanic cell Explain construction and working of galvanic cell with neat diagram calculate no of electrons are required for the deposition of 23 gm of aluminum

2005 53 The dissociation constant of a weak acid is 1 x 104 In order of prepare a buffer solution with a pH 5 the D 300 Salt Acid ratio should be 1 1 10 3 10 1 2 4 5 4 5 4

Enter your answer in the provided box If 37 0 ml of silver nitrate solution reacts with excess potassium chloride solution t precipitate what is the molarity of silver ion in the original solution

a Calculate the time for which a current of 0 65 A be passed through molten magnesium chloride to get 5 g of magnesium Given Mm Mg 24 25 g mol Draw a labelled schematic graph of a conductometric titration between a weak acid and a strong base

Which of the following statement is true for th electrochemical Daniel cell 1 Electrons flows from copper electrode to zinc electrode 2 Currents flows from zinc electrode to electrode copper 3 Cations moves towards the zinc electrode 4 All of the above

An electrolyte solution of XY with molality of 8 545 x 10 3 mol kg was electrolyzed in a Hittorf cell The mass of metal X molar mass and equivalent weight 112 4 deposited at the cathode was 0 01462g A solution weighing 113 25 g was withdrawn from the anode compartment and was found to contain 0 3321g of XY Calculate the transport numbers of the X and Y ions Molar mass and equivalent weight of electrolyte is 366 2

ZnSO4 CuSO4 IM IM The potential of the cell Zn was reported by Buckbee Surdzial and Metz as E 1 1028 0 641 x 10 3 T 0 72 x 10 5 T2 where T is the temperature in degree celsius Calculate AS for the cell reaction at 25 C a 45 32 c 25 43 Cu b 34 52 d 54 23

Given below are 2 conductometric titration plots In each plot conductance of a solution in flask is plotted on x axis shown as a and the volume of the titrant added from burette is plotted on y axis shown as b Which of the following option s is are correct Plot 1 Plot 2 C a a Plot I corresponds to titration of NaOH in flask versus HCl in burette Correct You Marked Plot 1 corresponds to titration of NaOH in flask versus mixed acid HCI CH3COOH in burette Plot 2 corresponds to titration of NaOH in flask versus HCI in burette Plot 2 corresponds to titration of NaOH in flask versus mixed acid HCl CH3COOH in burette

When 1 L of 1 3 M SnSO4 is electrolysed for a period of 10 minutes using a current of 96 5 A and inert electrodes the final concentration of Sn in the solution will be E 0 14 V E 0 13V Sn Sn4 EH7 0 0 4V Eso s 0 2 0V OH Sn Sn

Equal volumes of 0 015 M CH COOH 0 015 M NaOH are mixed together What would be the molar conductivity of mixture if conductivity of CH3COONa is 6 3 10 Scm K 1 8 4 S cm mol 3 4 2 S cm mol 2 84 S cm mol 4 42 S cm mol

73 R The concentration of H and concentration of OH of a 0 1 M aqueous solution of 2 ionised weak acid ionic product of water 1 10 14 1 2 x 10 3 M and 5 10 12 M 2 1 x 10 3 M and 3 10 11 M 3 0 02 10 3 M and 5 x 10 11 M X 4 3 x 10 2 M and 4 x 10 13 M 4

13 4 1 0 What is the standard electrode potential for the reduction of HCIO HCIO aq H aq 2e CT aq H2O 1 Given Cr aq Cr aq e E 0 41 V HClO aq H aq 2Cr aq 2Cr aq Cl aq H O 1 E 1 80 A 1 39 C 1 22 A A B 1 54 D 0 90 You Missed

Kinetics of acidic hydrolysis of ester is pseudo I order reaction CH3COOCH3 aq excess 1 H1 CH3COOH aq CH3OH aq Rate law is given by r K H H 0 CH3COOCH3 K 1 8 10 3 M 2 sec 1 where H ion concentration is given by acid catalyst In an experiment IM CH3COOCH3 is hydrolysed using 0 1M HCI as catalyst Reaction mixture is titrated against standard NaOH solution at different times If initially 10 ml of NaOH was required while after long time 100 ml of NaOH is required then find volume of NaOH required at 230 3 sec Options 1 O 91 ml 2 O 81 ml 3 O 75 ml

At 298 K and 1 bar partial pressure of hydrogen gas the half cell reduction potential of hydrogen electrode is equal to 0 30 V at pOH Take 2 303RT F 0 06 V at 298 K

The type of electrode Pb PbSO4 s H SO4 used in acid storage cell is 1 Metal electrode 42 2 Non metal electrode 3 Metal insoluble salt anion electrode dalom 00 3 Mo 4 Oxidation reduction electrode 0 Her

22 The advantages of fuel cells include 1 they can be recharged by the addition of more material to be oxidized and or reduced 2 they can be made to produce little or no harmful pollutants 3 they can be made to run very quietly 4 all of the above

In the electrolysis of concentration H SO4 solution 11 2 LH gas at 0 C and 1 atm is liberated at the cathode and 19 4 gm H S2Os is produced in the solution The volume in 7 at 27 C and 0 821 atm of O gas simultaneously liberated at the anode is 6

CI 39 The equivalent conductances of Ba 2 and are 127 and 76 2 cm 1 cm eq respectively at infinite dilution The equivalent conductance of BaCl at infinite as dilution will be CBSE AIPMT 2000 a 139 52 b 203 c 279 d 101 5

Electrolysis of an acetate solution produces ethane according to the Kolbe reaction 2CH COOC H 2CO 2e What volume in L of ethane is produced at 27 C and 760 mm Hg if a current of 0 500 A were passed through the solution for 10 hours and the electrode reaction is 96 5 efficient 6

The density of an equilibrium mixture of N O4 and NO2 at 1 atm and 373 5K is 2 0 g L Calculate Kc for the reaction N 04 8 2NO g If chemical equilibrium is attained at standard states then what is the value of AG Calculate the equilibrium concentration ratio of C to A if equimolar ratio of A and B were allowed to come to equilibrium at 300 K A g B g C g D g AG 830 cal A definite amount of solid NH4HS is placed in a flask already containing ammonia gas at a certain temperature and 0 1 atm pressure NH4HS decomposes to give NH3 and H S and at equilibrium total pressure in flask is 1 1 atm If the equilibrium constant K for the reaction NH4HS s NH3 g H S g is represented as zx 10 then find the value of z

Ag Ag Br BE0 01M CL0 2M AgCl 10 10 respectively Find which is are true for above cell at 25 C log 2 0 3 A As E A is not given so Ecell can not be determined Ag Ag if Kp of AgBr and AgCl at 25 C are 10 2 and 2 303 RT F B Elis 0 042 volt Ecell C AG 0 D E can not be determined as data is insufficient A A 0 06

4 H O H H O The emf of the cell reaction is 1 1 V Then calculate free energy change for the reaction Zn s Cu aq Zn aq Cu s 1 106 3 kJ 2 298 3 kJ 3 463 8 kJ 4 212 3 kJ What ard

Calculate the equilibrium constant for the Fe 2 Ce 4 reaction Fe 3 Ce 3 Given E Ce 4 Ce 3 1 44V and E Fe 3 Fe 2 0 68V Max score 2 Neg score 0 7 6x10 12 7 6 1012

v many grams of CaSO 4 may be produced from 3 78 g of SO the mass of iron in g which will be converted into Fe 304 by the action of 18 g of steam t What is the value of W 7 Fe H 0 Fe3O4 H culate the total moles of atoms of each element present in 122 5 g of KClO 3 dissolving 2 0 g of metal in sulphuric acid 4 51 g of the metal sulphate was formed The ific heat of the metal is 0 057 cal g C What is the valency of the metal 1 gram of a metallic chloride was found to contain 0 835 g of chlorine Its vapour density is 5 If its molecular formula is M Cl then what is value of x y

A 0 605 gm sample of Sodium Carbonate and Sodium bicarbonate the solution titrated with 0 106 N HCI 40 2 ml needed from the titrant to reach phenolphthalein and when titrated in presence of blue bromophenol found the total acid volume is 95 4 ml Calculate the for the constituents

The standard electrode potential E values of Al AI Ag Ag K K and Cr Cr are 1 66 V 0 80 V 2 93 V and 0 74 respectively the correct decreasing order of reducing power of the metal is NEET 2019 Odisha 1 Al K Ag Cr 2 Ag Cr AI K 3 K Al Cr Ag 4 K AI Ag Cr

Excess F g reacts at 150 C and 1 0 atm pressure with Br g to give a compound BrF If 423 mL of Br g at the same temperature and pressure produced 4 2 g of BrF what is n Atomic mass Br 80 F 19

4 9 Molar conductivity of a solution of an electrolyte AB is 150 59 AB facen at sige nachal on s cm mol If it ionises as AB A 3B its equivalent cm mol AB A conductivity will be arguratat at grain 1 150 in Scm eq 2 75 in Scm eq 3 50 in Scm eq 4 80 in Scm eq 1 150 in Scm eq 2 75 in Scm eq 3 50 In Scm eq 4 80 In Scm eq

95 The following facts are available 2A B 2B A 2C B No reaction 2D A 2A D Which of the following statements is correct 1 EC IC EB 1B E10 2 EC IC EB 1B EA 1A E 1D 3 EC IC E B EA 1A E 10 FO FO 4 F EO A A FO 50

Am of 0 01 M MgCl2 is 220 S cm mol 1 A of MgCl is 240 S cm mol 1 A of Mg2 is 100 S cm mol 1 All above measurements are done in a conductivity cell Assuming MgCl2 to be a strong electrolyte which of the following is are incorrect Limiting equivalent conductivity of MgCl is 480 S cm eq 1 Am of MgCl2 varies linearly with its concentration Am of 0 04 M MgCl2 will be 160 S cm mol 1 Am of 0 04 M MgCl2 will be 200 S cm mol 1

Given below are two statements Statement I The E value of Ce4 Ce3 is 1 74 V Statement II Ce is more stable in Ce4 state than Ce state In the light of the above statements choose the most appropriate answer from the options given below 1 Both statement I and statement II are correct 2 Statement I is incorrect but statement II is correct 3 Both statement I and statement II are incorrect 4 Statement I is correct but statement II is

4 An aqueous solution of AgNO js electrolysed using direct current The electrodes are inert and time dependence of current is represented as Ag N 03 1 0 J Current 1 amp 4 2 5 10 15 Time sec The mass in mg of Ag 108 g mol deposited at

Let CNaCl and CBaso be the conductancesongo mathongo in S measured for saturated aqueous solutions of NaCl and BaSO4 respectively at a temperature T Which of the following is false mnothonge A CBaSO4 T BaSO4 T for T T B CNaCl T CNaCl T1 for T T C CNaCl CBaSO4 at a given T D lonic mobilities of ions from both salts increase with T

32 Calculate the cell emf in mV for pt H 1 atm HC1 0 01 M AgCl s Ag s at 298 K if AG values at 25 C are 109 56 KJ mole for AgCl and 130 79 KJ mole OSR IIT CO SC Page No

of 0 01 M MgCl is 220 S cm mol of MgCl is 240 S cm mol 2 of Mg is 100 S cm mol All above measurements are done in an conductivity cell Assuming MgCl to be a strong electrolyte which of the following is incorre A Limiting equivalent conductivity of MgCl is 480 S cm eq B of MgCl varies linearly with its concentration C of 0 04 M MgCl will be 160 S cm mol D 2 of 0 04 M MgCl will be 200 S cm mol A

50 75 For the redox reaction Zn s Cu 0 1M 2 1M Cu s taking place in a cell E is 1 10 Volt E for the cell will be 010591 1 1 80 volt 2 1 07 volt 40 Ne 3 0 82 voit 4 2 14 volt

By how much times will potential of half cell Cu Cu change if the solution is diluted 100 times at 298 K A Increases by 59 mV B Decrease by 59 mV 42 C Increases by 29 5 mV 70 71 D Decreases by 29 5 mV

0 5 mole of electron is passed through two electrolytic cells in series One contains silver ions and the other zinc ions Assume that only cathode reaction in each cell is the reduction of the ion to the metal How many gm of each metals will be deposited

The same amount of electricity was passed through two separate electrolytic cells containing solution of nickel nitrate Ni NO Jand chromium nitrate Cr NO respectively If 0 3 g of nickel was deposite in the first cell the amount of chromium deposited is kohlaw law at wt of Ni 59 at wt of Cr 52 A 0 1 g B 0 17 g C 0 3 g D 0 6 g

Which of the following represents the reduction potential of silver wire dipped into 0 1 M AgNO solution 0 0351 toy Ag Cau tieu at 25 C e Ag Ay 1 D E A E red B E 0 059 red C E OXI 0 059 red 0 059 3

entify the true statement s among the following A B C D 2 for a strong electrolyte in water m decreases as the electrolyte concentration increases At low concentrations conductivity for a strong electrolyte in water increases as the electrolyte concentration increases Conductivity for a strong electrolyte in water always increases as the electrolyte concentration increases for a weak acid HX 200 200 YOU M YOU M YOU M YOU M

Which of the following will increase the voltage of the cell with following cell reaction Sn 2Ag Sn 2 2Ag s aq A Decrease in the concentration of Ag ions B Increase in the concentration of Sn 2 ions C Increase in the concentration of Ag ions D A B both

interconnecting them through In two vessels each containing 500ml water 0 5m mol of aniline K 10 9 and 50mmol of HCI are added separately Two hydrogen electrodes are constructed using these solutions Calculate the emf of cell made by connecting them appropriately of the following cell

46 The following facts are available 2A B 2B A No reaction 2C B 2D A 2A D Which of the following statement is correct 1 EO C C 2 EC IC C C 3 E E B B2 E B B E B B E ATA E E E E A A ATIA D D D D E DVD

20 mintue What mass of Ni is deposited at the cathode A current of 3 7A is passed for 6hrs between Ni electrodes in 0 5L of 2M solution of Ni NO3 2 What will be the molarity of solution at the end of electrolysis NICE

A constant current of 30 A is passed through an aqueous solution of NaCl for a time of 1 0 hr How many grams of NaOH are produced What is volume of Cl gas at 1 atm 273K produced in litre If 0 224 litra II

Assume 96500 C as one unit of electricity If cost of electricity of producing x gm Al is Rs x v is the cost of electricity of producing x gm Mg Chromium metal con ho plated out from on aidia olution containing CrO according to follo

Electro chemistry The electrosynthesis of MnO is carried out from a solution of MnSO4 in H SO4 aq If a current of 25 5 ampere is used with a current efficiency of 85 how long would it take to produce 1 kg of MnO

Given electrode potentials Fiely 4 m Fe e aq aq E for the cell reaction Fe E 0 771 volts aq aq aq 2Fe 21 2Fe I A 2 x 0 771 0 536 1 006 volts C 0 771 0 536 0 235 volts 1 2e21 E 0 536 volts Go SPP SOP Ording tot anode Cathode is B 0 771 0 5 x 0 536 0 503 volts D 0 536 0 771 0 235 volts