Physical Chemistry Questions

2 In a cell that utilises the reaction Zn s 2H aq Zn aq H g addition of H SO4 to cathode compartment will 1 increase the Ecell and shift equilibrium to the right 3 lower the E and shift equilibrium to the left cell 2 lower the Ece and shift equilibrium to the right 4 increase the Ecell and shift equilibrium to the left cell

For the reaction R P the concentration of reactant changes from 0 03 M to 0 02 M in 25 minutes Calculate the average rate of reaction using units of time both in minutes and seconds

29 In a cubic crystal of A and B A atoms are arranged at the corners and edge centres while B atoms are arranged at alternate face centres and body centre What will be the formula of compound 1 AB 3 A B 2 A B 2 4 A B

47 AG of reversible reaction at its equilibrium is 1 Positive 3 Always zero 2 Negative 4 May be 1 or Pyt Itd Regd Office Aakash Tower 8 Pusa

a Which of the following statements about pH and H ion concentration is incorrect 2000 Addition of one drop of concentrated HCl in NH OH solution decreases pH of the solution A solution of the mixture of one equivalent of each of CH COOH and NaOH has a pH of 7 c pH of pure neutral water is not zero b d A cold and concentrated H SO4 has lower H ion concentration than a dilute solution of H SO

38 What is true for solutions showing negative deviation from ideal behavior 1 Point the vapour pressure of individual O components in solution is higher than pure components the vapoure pressure of individual component in solution is lower than pure component the boiling point of the azeotrope is lower than either of the individual component The vapour pressure of the less volatile component is higher than the more volatile component

Chem Section A This section contains 35 SINGLE CO questions Each question has 4 choic Read More Copper matte contains Cu 0 and Fe203 O Cu S and Fes Cu 0 and Cu S

1 Read the passage given below and answer the following questions 1 4 4 A galvanic cell consists of a metallic zinc plate immersed in 0 1 M Zn NO3 2 solution and metallic plate of lead in 0 02 M Pb NO3 2 solution The following questions are multiple choice questions Choose the most appropriate answer i How will the cell be represented a Zn s Zn aq Pb aq Pb s b Zn s Zn aq Pb aq Pb s c Pb aq Pb s Zn s Zn aq d Pb s Pb aq Zn s Zn aq ii Calculate the emf of the cell a 6 01 V c 0 609 V iii What product is obtained at cathode a Zn 0 412 V b d 4 12 V b Pb d Pb c Zn iv Which of the following statement is not correct about an inert electrode in a cell a It does not participate in the cell reaction b It provides surface either for oxidation or for reduction reaction c It provides surface for conduction of electrons d It provides surface for redox reaction

A rigid tank of 1 5 kg steel holds 0 75 kg ammonia at 800 kPa as saturated vapor The tank is now heated to 260 degrees Celcius by heat transfer Determine the amount of work and the heat transfer in the process

Tollen s test is given by aldehydes Ag e Ag Ered 0 800V C6H O6 H O CH O 2H 2e E 0 05V 12 12 7 Ox Ag NH eAg 2NH FFF RT use 38 9V Answer the following questions On adding NH pH of the solution increases to 11 then identify the effect on potential of half E increased by Ex by 0 65 V OX B E decreased by E by 0 65 V OX OX C Ered increased by Ered by 0 65 V E 0 373V red D Ered decreased by Ered by 0 65 V

50 ml of 0 6M acetic acid is shaken with 0 5g of activated charcoal The final concentration of solution after adsorption is 0 3M The amount of acetic acid adsorbed per gram charcoal is M wt of acetic acid is 60 1 0 45 g 2 3 6 g B 0 9 g 4 1 8 g

The half life period of a first order chemical reaction is 6 93 minutes The time required for the completion of 99 of the chemical reaction will be log 20 30 O 23 03 minutes O46 06 minutes O 460 6 minutes 030 3 minuton

The activation energy of a certain reaction is 35 1 kJ mol At 26 C the rate constant is 0 0180s temperature in degrees Celsius would this reaction go twice as fast Express your answer with the appropriate units At what

Zn Zn Ag Ag 0 01 M 1L 0 1 M 1 EAg Ag 0 8 V E2 2n 0 77 V If x L of H O is added in anodic chamber and y L of H O is added in cathodic chamber such that emf of ce more than Ecell The possible value of x and y are X A 90 B 25 C 31 D 13 y 10 4 5 3

Solid Hgl is gradually added to KI solution in Nessler s test Which of the following statements is wrong A B C D Freezing point increases and then becomes constant Freezing point decreases constantly Boiling point decreases and then becomes constant Vapour pressure increases to a constant value Correct Answer Your Answer

min 1 4 4 6 x 10 min 53 The activation energy of a certain reaction is 50 kJ mol 1 in the absence of catalyst at 27 In the presence of catalyst the activation energy becomes 20 kJ mol 1 at the same temperature The temperature at which rate of uncatalysed reaction becomes equal to the rate in presence of catalyst at 27 C is Assume Arrhenius parameter A remains constant 1 500 K 3 250 K 2 750 K 4 1000 K

Board Competitive Exa DH 48 Latent heat of fusion of ice is 0 333 kJ g The increase in entropy when 1 mole water melts at 0 C will be 1 21 98 kJ K mol 2 21 98 kcal K mol 3 21 98 JK mol 4 21 98 cal K mol The bo oint

Knowing precisely all the components of a non zero angular momentum of the electron in a hydrogen atom would violate Heisenberg s uncertainty principle The radial probability distribution function P r is maximum at r ao for the ground state of hydrogen atom however y attains maximum value at a different value of T 5 s orbital has angular independence i e for s orbital wave function is independent of and 8 9 AV BY D In the radial probability distribution function plots if n is the number of times the wave function changing its sign then number of radial nodes for that orbital is n 1

Match the following Column l A Physisorption B Chemisorption C Desorption D Adsorption isotherm S Solla sol Column l p Multilayer adsorption q Plot of T vs P for a given amount of ads r Strong covalent forces s Occurs at high temperature

29 29 Correct statement about heat and work is that 1 Heat appears at surface only and work in bulk 2 Heat appears in bulk and work only at surface 3 Both heat and work appear in bulk of system 4 Both heat and work appear on surface only e

1 62 g of green algae absorbs 6 10 3 mol CO per hour by photosynthesis If the fixed C atoms are all stored after ph otosynthesis as starch C6 H10 05 ho w long will it take for the algae to doubl e their own weight Mw of C6 H10 05 n 162n The part of equation involved is 6nCO C6H1005 1 62gof C6H1005 Mol of CO absorbed 1 620f C6H1005 1 62 1 6n must be produced to double the weight per hour 1mol starch 6nmol CO 162ngstarch mol starch note the n is cancelled 162n 0 06mol CO Time required 0 06molC0 1 6 x 10 molCI 10h Please explain did you get Third Step 1 62 of C6H1005 n 1 mol starch 162

ce energy Which condition favours the bond formation where Fa force of attraction and Fr fc repulsion a Maximum potential energy and Fa Fr c Minimum potential energy and Fa Fr b Minimum potential energy and Fa d None of the above

According to Henry s law the partial pressure of the gas in vapour phase p is proportional to the mole fraction of the gas x in the solution For different gases the correct statement about Henry s constant is Question Type Single Correct Type 1 2 3 4 Higher the value of KH at a given pressure higher is the solubility of the gas Higher the value of KH at a given pressure lower is the solubility of the gas KH is not a function of nature of gas KH value for all gases is same at a given pressure

One mole of O g initially at a temperature of 120 K and under a pressure of 4 atm is expanded adiabatically to 1 atm in such a way that the temperature of the gas falls to 90 K just above its normal boiling point C of O g is 28 2 JK mol and is constant over the required temperature range O g is supposed to behave ideally Choose the correct options log 2 0 3010 log 3 0 4771 q 0 W 597J AH 846 J AS 342 18

Select the correct statement s A Compressibility factor for one mole of Vander Waal s gas at critical state is 3 8 B Compressibility factor for two moles of Vander Waal s gas at critical state is 3 C Vander Waal s gas molecule always exerts lower average force per collision or the wall than ideal gas molecule when mixture of one mole of each of them is taken in a container at same temperature D Mixture of two equimolar Vander Waal s gases has critical temperature less

c the stress he bears during the travels d sweet memories of the past iii The poet is a person who is free from all inhibitions Discuss concept of freedom is expressed in the poem 95

In a solid AB A atoms have ccp arrangement and B atoms occupy all the octahedral sites If all the face centred atoms along one of the axes passing through body centre are removed then what will be the resultant stoichiometry of compound introc

C5 The interionic distances cation and anion are given below AB 3 67 DF 3 14 AC 3 44 EF 2 79 DC 3 29 EG 2 31 The radius of B ion is 2 19 2021 06 Choose the correct answer 1 The radius of G ion is 1 1 81 A 3 1 33 2 The radius of A ion is 1 1 33 3 1 96 2 1 96 4 0 98 2 1 48 4 1 54 8

This section contains 35 Sl questions Each question has 4 choices 1 2 Read More German silver contains O 60 70 Zn 15 20 Cu 15 20 Ni 30 40 Zn 20 25 Al 40 45 Cu O 40 50 Ni 25 30 Zn 25 30 Cu 25 30 Ni 25 30 Zn 40 50 Cu

31 The enthalpy of reaction is maximum in which of the following reaction exceptiona 1 NaOH HCl NaCl H O 2 NaOH HF NaF H O 3 NaOH HBr NaBr H O 4 All have same value AH a A

4 Given the following concentrations note the abnormal values for Nat in the ICF and K in the ECF K 150 mM ICF ECF 1 5 mM b In the case above if the membrane is permeable only to K what would be the predicted membrane potential Na 50 mM 160 mM a Calculate the equilibrium potentials of K Na CI using the Nernst equation Logarithm table Ex log 0 01 2 log 0 1 1 log 1 0 log 3 2 0 5 ENa log 10 1 Ec log 100 2 c If the membrane is equally permeable to K and Cr and impermeable to all other ions what would be the predicted membrane potential CI 15 mM 150 mM

100 mL of PH when completely decomposed produces phosphorus and hydrogen The change in volume of the gas is PH g P s 3 H g 1 50 ml increase 3 900 ml decrease 2 500 ml decrease 4 Does not changes

The entropy of a crystal containing one mole of identical molecules was measured to 9 134 J K at OK How many orientations does each molecule have in the crystal b Draw a molecule which would be expected to exhibit such behavior

questions Each question has 4 choices 1 2 Read More In Freundlich adsorption isotherm the slope of the plot and log P is between log On O 0 X 1 m

0 1 M solution of KI reacts with excess of H SO4 and KIO3 solutions according to equation 51 IO3 6H 31 3H O Which of the following statements is incorrect a 200 mL of the KI solution reacts with 0 004 mole of KIO3 b 100 mL of the KI solution reacts with 0 006 mole of H SO4 c 0 5 litre of KI solution produce 0 05 mole of I d Equivalent weight of KIO3 is equal to Molecular weight 5

Here N is the number of electrons having parallel spins As the number of parallel spins increases the exchange energy also increases The exchange means the shifting of electrons from one orbital to another in the same sub shell This can be easily illustrated by considering chromium as example If the configuration is 3d 4s N is taken as 5 and C pairs of electrons equal to 10 is possible The exchange energy is 10K If the configuration is 3d5 4s N is taken as 6 and C pairs of electrons equal to 15 is possible The exchange is 15K

34 90 Consider the process E x Volt BrO3 Value of Mark for Review E Bro3 2Br x1 x Volt Bro is O 2 x x 3 Volt 4 x x Volt 4x x Volt 5 E x Volt TIN 01 hr Br

36 If 0 25 molar aqueous solution of Na2SO4 is isotonic with 7 5 w v solutio of non electrolyte and non volatile solute at 298 K then molar mass in g mol 1 of solute is 1 10 2 100 3 90 4 400

4 moles of a mixture of FeSO4 4 0 moles of a mixture of FeSO4 to FeC2O4 is completely oxidised by 1 mol of Ba MnO4 2 in the acidic medium What is the molar ratio of FeSO4 to FeC 04 in the given mixture A B 1 2 2 1

Chem This section contains 35 SINGLE CORRECT TYPE questions Each question has 4 choices 1 2 Read More The protecting power of lyophilic colloidal sol is expressed in terms of O Critical micelle concentration O Oxidation number O Coagulation value

An unknown composition of mixture of CS H S was burnt in sufficient amount of 0 The resulting gases found to exert a pressure of 1 97 atm in a 20 lit vessel at 400 K The gaseous mixture required 2 8 M 12 solution and 250 ml of it was required to reach the end point forming I Mole fraction of CS in the original mixture is X Value of X

At 298 K for the gas phase reaction 2SO g O g 2SO3 g 1 Kp 4 x 1024 atm If SO2 g pressures O2 g and SO3 g at partia of 2 1 and 2 atm respectively are mixed and allowed to attain equilibrium the approximate partial pressure of SO g at equilibrium is A 10 8 C 2 10 12 B 2 x 10 8 D 10 2

SolveLancer Test A student measures the volume of a solution The recordings came out to be 50 1 mL 50 2 mL 49 9 mL and 50 3 mL in the first second third and fourth trial respectively Identify the correct statement if the volume of the liquid is 50 0 mL SolveLancer Test a He has good precision b He has good accuracy c He has good accuracy and precision d He has neither accuracy nor precision

100 ml of 0 1 M HCI is neutralised by 50 ml 0 2 M NaOH solution at 25 C The temperature of the final solution is increased by specific heat capacity of H O 4 2 JK g Assume density of final solution density of water and Mass of final solution Mass of water 1 0 2 K 2 9 K 3 09 K 4 4 2 K

A lead battery recycling plant has decided to have an ion exchange column based wastewater treatment system to remediate Pb The average concentration of Pb in the effluent is 0 02 mol dm3 and the average flow rate is 28 L h I List four fundamental requirements of an ion exchange resin II For initial evaluations of the strong cation exchange resin the total static capacity needed to be evaluated theoretically The unit molar mass of the resin is 184 g mol What is the theoretical total static capacity of the resin for Pb ions in meq g units

Dilution process of different aqueous solutions with water are given in List I The effects of dilution of the solutions on H are given in List II Note Degree of dissociation a of weak acid and weak base is 1 degree of hydrolysis of salt 1 H represents the concentration of H ions Column I 10 mL of 0 1 M NaOH 20 mL P A of 0 1 M acetic acid diluted to 60 mL the value of 20 mL of 0 1 M NaOH 20 mL change to half of B of 0 1 M acetic acid diluted to 80 mL its initial value dilution 20 mL of 0 1 M HCl 20 mL c Of 0 1 M ammonia solution diluted To 80 mL 10 mL saturated solution of Ni OH 2 in equilibrium with excess solid Ni OH 2 is diluted to 20 mL solid Ni OH 2 is still present after Dilution Column II the value of H P does not change on dilution S P the value of H changes to two R times of its initial Value on dilution S the value of H 1 to times of 2 its initial value on dilution The value of H Changes to 2

Which of the following is correct for critical temperature AY It is the temperature at which liquid and vapour can coexist BY Beyond the critical temperature there is single phases and a gas cannot be liquified by compres C Below critical temperature Tc the gas can be liquified at all pressure D At critical point the gas and the liquid phases have different critical densities

same for first second and third order reactions Which one is true at a definite moment for rate of these three reactions if concentration of reactants is same and less than 1 M Question Type Single Correct Type 1 2 3 r r2 13 r1 r2 r3 r r2 r3 None of these

d 39 Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations 2018 a 60 mL b 55 mL c 75 mL MR MR MS 100 mL HC1 40mL HC1 45 mL HC1 25 mL M 10 M 1 10 M 5 NaOH HCl 100 mL NaOH M d NaOH 10 pH of which one of them will be equal to 1 NaOH M 10

The heat of neutralisation of four acids P Q R S are 13 7 9 4 11 2 and 12 4 kcal respectively they are neutralised by a common base The acidic character obeys the order 1 P Q R S 2 P S R Q 3 S