Physical Chemistry Questions

2 C H NH 3 C H OH 4 C H CI of urea are present in 100 mL of its solution The concentration of urea 1 C H NH 6 02 x 100 molecules solution is 1 0 02 M 2 0 001 M 3 0 01 M 4 0 1 M What mass of Agl will dissolve in 0 1 L of 1 0 M NH3 Neglect change in conc of NH3 Atomtextc weight of Ag I are 108 amu and 127 amu respectively

At a certain temperature this reaction establishes an equilibrium with the given equilibrium constant Kc 3A g 2B g 4C g Kc 1 73x1029 If at this temperature 2 10 mol of A and 3 90 mol of B are placed in a 1 00 L container wha are the concentrations of A B and Cat equilibrium

58 180 If heat of combustion of methane is 890 kJ mol then amount of heat released when 13 2 g of CO is produced on combustion of methane is 267 kJ 315 kJ 420 kJ Mark for Review 175 kJ

gy in the 2nd 2 3 4 eV 4 13 6 eV tic energy and the total aydrogen atom acco 44 Maximum frequency of emission is obtained for the transition 1 n 1 n 3 n 2 to n 1 2 to n 1 1 to n 2 2 n 6 to n 2 4 n 2 to n 6 per 45 If the ionization energy of hydrogen is 313 8 kcal 54

52 0 1 M NaCl and 0 05 M BaCl solutions are separated by a semi permeable membrane in container For this system choose the correct answer 1 Water flows form BaCl soltion towards NaCl solution 2 There is no movement of any solution across the membrane 3 Osmotic pressure of 0 1 M NaCl is lower than the osmotic pressure of BaCl Assume complete dissociation 4 Water flows from NaCl solution towards BaCl solution

For the reaction AB g A g B g AB is 33 dissociate at a total pressure of P Therefore P is related to K by one the following options 1 P 3K 2 P Kp 3 P 8K 4 P 4Kp

Two parallel disks 50 cm in diameter are separated by a distance of 12 5 cm and enclosed by a large room at 300 K One disk is maintained at a constant temperature of 800 C and has an emissivity of 0 8 The other disk is perfectly insulated and has an emissivity of e 0 1 Calculate the net radiant energy lost by the disk maintained at 800 C

10 18 Conductivity of 0 01 M NaCl solution is M 0 00147 ohm cm What happens to this conductivity if extra 100 mL of H O will be added to the above solution a Increases b Decreases c Remains unchanged

A current of 2 50 A was passed through molten aluminum III oxide for 4 25 hours decomposing the compound into aluminum metal and oxygen p a Write the balanced electrode equations stating which reaction occurs at the anode and which occurs at the cathode 2 marks b Using your equations together with the data given calculate the mass of aluminum metal produced from this electrolysis process 2 marks

Choose the 1 Correct expression for density of unit cell of CsCl in terms of radius of Cs r and radius of CI r in pm and NA Avogadro s number is density is in g cm MCSCI 3 1 2 r r NA 2 3 4 2MCSCI 3 2 r r NA X10 30 McSci 3 2 r r NA X 10 2MCSCI 3 13 AL 12 I In 30

7 How is the following transformation best carried out 1 OsO NaHSO 2 H SO H O 3 H SO H SO 4 HIO 3 Select the reagent used to bring about the following transformation But 2 ene to ethanol

If 1 5 mols of gas is allowed to expand to twice its original volume while in contact with a thermal bath what is the change in entropy of the gas Provide your answer in units of the gas constant R do not include R in your answer

neet prep High Yieldin 107 The work done in ergs for the reversible expansion one mole of an ideal gas from a volume of 10 liters to 2 liters at 25 C is 1 2 303 x298 0 082 log 2 2 298 x 107 x 8 31 x2 303 log 2 3 2 303 x298 x 0 082 log 0 5 4 8 31 x 107 x 298 2 303 log 0 5

For a reaction N g 3H g rate of consumption of N will be 1 3 10 2 mol dm s 3 3x10 mol dm s 2NH3 g the rate of formation of NH3 was found to be 2 x 10 2 mol dm s The L 2 1 x 10 2 mol dm s 4 x10 mol dm s otion vessel is sudd

Problem 34 Pay load is defined as the difference between the mass of displacce air and the mass of the balloon Calculate the pay load when a balloor of radius 10 m mass 100 kg is filled with helium at 1 66 bar at 27 C Density of air 1 2 kg mand R 0 083 bar dm K mol

Which of the following is not true as per the kinetic theory of gases V container Vvacant space F van der Wall F dipole dipole 0 KE average Constant at cont temperature Position and time relationship can not be given for a given particle of gas

11 If the wave number of 1st line of Balmer series of H atom is x then 108 x A Wave number of 1st line of lyman series of the He ion will be 5 36x B Wave number of 1st line of lyman series of the He ion will be 5 5 C The wave length of 2nd line of lyman series of H atom is 32x 32x D The wave length of 2nd line of lyman series of H atom is

electron position is en momentum which the uncertainty in electron 9x10 28g 1x 109 cm s 1 According to the Bohr Theory which of the following transitions in the hydrogen atom will give rise to the least energetic photon 1 n 5 to n 3 3 n 5 to n 4 IS 2 n 6 to n 1 4 n 6 to n 5 Yn 2011

2p 11 present in 139 Which of the following set of quantum numbers is correct for the 19th electron of Chromium S 1 2 1 2 1 2 10 n 1 3 2 3 3 4 l 0 2 0 m 0 2 0

In NaCl structure CI form the C C P lattice Which of the following change in NaCl structure occur so that formula become Na3Cl2 Ignore electrical neutrality If particles along one body diagonal are removed If particles along two fourfold axis are removed Particle along one face diagonal plane is removed If particles along one fourfold axis are removed

A silver electrode is immersed in a 0 1 M AgNO solution at 25 C If AgNO3 dissociates almos completely in the solution then determine the potential of the silver electrode 0 Ag Ag Given E 0 80 V

BEGINNER S BOX 6 A neutral atom of an element has 2K 8L 11 M and 2N electrons The number of p electrons in the atom are 1 2 212 3 10 4 6 An atom has 2 electrons in K shell 8 electrons in L shell 8 electrons in M shell The numbe

3 A high pressure cell has a volume of 0 33 ft and contain gus cet 2500 psice and 130 F cet which conditions its 2 factor is 0 75 when 43 6 scf of the gas croe bled from the cell the pressure droped to 1 1000 Psia the tem pesuture 130 F what is the gas deviction factor cet Remaining at 1000 Psia and 130 F 2

Which of the following order is incorrect according to MOT 1 B B F F Bond Energy 2 B B F F Bond Length 3 N N 0 0 Bond Energy 4 C C 0 0 Bond Length

Acid 1 has a pKa value of 6 Acid B has a pKa value of 2 Which statement below is accurate O Acid B is 100 000 000 times weaker than acid A O Acid B is 80 times stronger than acid A O Acid B is 100 000 000 times stronger than acid A O Acid B is 80 times weaker than acid A O Acid B is 8 times stronger than acid A Acid B is 8 times weaker than acid A

3 Nylons are usually hydrophobic The final product III obtained in the reaction H CH H 11 CH C C 0 CH CH C 0 1 CH 1 CH3 CH3 C CH CHCH CH OH CH OH CH3 H O NaBH CH3 C CH CH CH OH CH 3 CH 3 4 Nylons have very high mechanical strength II III is 2 CH3 CH3 C CH C CH OH CH CH 3 CH 3 CH3 C CH CH CH OH CH

What is the Bronsted Lowry definition of an acid Any substance that releases H ions when dissolved in water A proton acceptor A proton donor O Any substance that releases OH ions when dissolved in water O An electron donor An electron acceptor

Which of the following is an appropriate set of reactants for the preparation of 1 methoxy 4 nitrobenzene NO CH ONa 1 A NO CH Br 2 B 3 Both 1 and 2 4 none of these

A certain boiler employs one hundred 2 cm diameter tubes 1 m long The boiler is designed to produce local forced convection boiling of water at 3 MPa pressure with ATX 10 C Estimate the total heat transfer rate and the amount of saturated vapor that can be produced at 3 MPa ww

The correct order of increasing hydration energy of the following conjugate bases of oxoacids of chlorine is 1 CIO CIO CIO CIO 2 CIO CIO CIO CIO 3 CIO CIO CIO CIO 4 CIO CIO CIO CIO

25 mL of a solution of Na CO3 having a specific gravity of 1 25 g mL require 32 9 mL of a solution of HCI containing 109 5 g of the acid per litre for complete neutralization Calculate the volume of 0 84 N H SO4 that will be completely neutralized by 125 g of Na2CO3 solution A 420 mL B C skipped 520 mL 470 mL

k 5 757 10 1 In a second order reaction both the reactants have equal initial concentration for 60 completion of reaction is 3000 second What will be the time taken for 20 of the reaction ka 1 Let a 1

Identify the correct statements regarding the structure of Al BH 1 Al is sp d and B is sp hybridized 2 It has 6 3c 2e bonds 3 It has 6 Al H Bbonds bonds 4 It has 6 2c 2e 1 Only 1 3 4 2 Only 1 2 3 3 Only 1 2 4 4 All of 1 2 3 and 4

4 SO SO SO HSO 3 H SO H SO SCL H The degree of hardness of water is usually expressed in terms of 1 g L of CaCO and MgCO present 2 ppm by weight of MgSO 3 ppm of CaCO actually present in water 4 ppm by weight of CaCO irrespective of whether it is actually present

The air pollutant NO is produced in automobile engines from the high temperature reaction N2 g O2 g 2NO g Kc 1 7x10 3 at 2300 K Calculate the equilibrium concentration of NO if the initial concentrations are 2 23 M N2 and 0 55 M O2 This N2 02 concentration ratio is the ratio found in air

What is the Arrhenius definition of an acid O An electron acceptor A proton donor O Any substance that releases OH ions when dissolved in water O A proton acceptor O An electron donor

The reduction of iron III oxide Fe O3 to pure iron during the first step of steelmaking 2 Fe O s 4 Fe s 30 g s driven by the high temperature combustion of coke a purified form of coal C s O g CO g uppose at the temperature of a blast furnace the Gibbs free energies of formation AG of CO and Fe O are 411 kl mol and 825 k espectively Calculate the maximum mass of pure iron that can be produced by the combustion of 8500 kg of coke ound your answer to 2 significant digits kg

For a reaction A Product graph of concentration of reactant versus time is given Concentration of reactant M 0 04 0 03 0 02 0 01 200 Time s The rate in Ms of reaction after 53 34 seconds

Phosphoric acid H3PO4 is a triprotic acid with pKa values of 2 12 7 21 and 12 32 It is a useful buffer solution for pH values near the pKa values You have a 0 100 M solution of phosphate buffer with a pH of 2 50 How many mL of 0 500 M NaOH solution must be added to 1 00 L of this buffer solution to convert it to a buffer at pH 7 70

A working electrochemical cell Ecell 0 is formed by zinc and silver electrode In this cell zinc electrode is dipped in 0 1 M ZnSO4 and silver electrode is dipped in 0 1 M AgNO3 solution as Om Zn If the emf of cell at 298 K is x Then the value of 100x to the nearest integer in V is 4 E22 Zn 0 76 V EO Ag Ag Ag 0 8 V

3 If 0 15 g of a solute dissolved in 15 g of solvent is boiled at a temperature higher by 0 216 C than tha of the pure solvent The molecular weight of the substance molal elevation constant for the solvent is 2 16 C is 1 100 2 80 3 10 4 1 001

CHEMISTRY Microcosmic salt bead test of salt X yields semi translucent mass Therefore it contains 1 Co NO3 2 4 MnSO4 2 Ca NO3 2 3 CuSO4 CH H C Cl hv CH N isomeric products CH Cl M isomeric products

A ball of mass m is dropped onto a smooth fixed wedge of inclination 0 The collision is perfectly elastic If after the collision The x component of the velocity of the block is 2gh than 0 is Fixed 1 30 M m 0 2 45 3 60 4 15

The molar conductivity of 0 02 M HCOOH is 40 4 S cm mol If A H 350 S cm mol and m A HCOO 54 S cm mol then dissociation constant of HCOOH is 1 2 22 x 10 3 3 2 22 x 10 5 2 2 22 x 10 4 4 1 22 x 10 FC0204

If same type of atoms are packed in hexagonal close packing and cubic close packing separately then a density of hcp will be greater than ccp b density of hcp will be smaller than cep c density of hcp will be equal to ccp d density of hep and ecp will depend upon the temperature of the system COMEDK

2016 82 Lithium has a bcc structure Its density is 530 kg m and its atomic mass is 6 94 g mol Calculate the edge length of a unit cell of lithium metal N 6 02 1023 mol a 527 pm c 154 pm b 264 pm d 352 pm NEET Phono

27 Assertion The number of tetrahedral voids is double the number of octahedral voids Reason The size of the tetrahedral voids is half of that of the octahedral void a If both assertion and reason are true and reason is the correct explanation of assertion b If both assertion and reason are true but reason is not the correct explanation of assertion If assertion is true but reason is false c

3 CaCO MgCO CaO MgO 2CO 4 2Cu S 30 2Cu O 2SO The logarithm of the equilibrium constant of the cell reaction corresponding to the cell aq Y s with standard cell potential E 1 2V is given by X s X aq 1 40 2 2 47 2 3 12 5 4 21 5

A certain mass of an ideal diatomic gas contained in a closed vessel is heated i t is observed that the temperature rema ins constant However half the amount of gas gets dissociated the ratio of the heat supplied to the gas initial internal energy of the gas will be

58 Assertion bcc and hcp has same packing efficiency Reason Both have same number of atoms per unit cell and same arrangement a If both assertion and reason are true and reason is the correct explanation of assertion b If both assertion and reason are true but reason is not the correct explanation of assertion If assertion is true but reason is false c d If both assertion and reason are false AIMS