Physical Chemistry Questions

Zero Marks An organic compound CxH2yOy molar mass 150 gm mol was burnt with twice the amount of oxygen needed for complete combustion to CO and H O The hot gases when cooled to 0 C and 1 atm pressure measur x 2y 2 24 litres The water collected during cooling weighed 0 9 g Find the value of 2

3 95 g 4 39 g If I mole A and 4 mole B on mixing have total 67 pressure is 75 torr vapour pressure of pure A is 200 torr and vapour pressure of pure B is 50 torr Which of the following is correct 2 AHmix ve 4 AV mix ve N 5 1 AS ve 3 AGx ve 100 ml each of 0 5 N NaOH HCC and 10 68 3 93 g af 1 mole A4 mole B 75 torr B 50 torr 1 AS ve 3 AGmix ve N 0 5 N NaOH HC 4 39 g he 200 torre 2 AH ve 4 AVmax ve N T H SO

2 QUESTION 5 Pls calculate arrange below substances by increasing of lattice energy using

3 100 cm of 1 M CH3 COOH was mixed with 100cm of 2M CH3 OH to form an ester The change in the initial rate if each solution is diluted with equal volume of water would be Yez Gal 4 fac 1 M CH3 COOHT 100 cm 2MCH3OH 100cm uz en una gran a 0 5 times c 0 25 times erar del b 2 times d 4 times

83 ALLEN Phenol is dimerised to 60 in a solvent the 83 observed moleculer weight of phenol will be 1 134 2 2 Less than 94 3 100 4 150 Which of the following in la Sayfa WATER 1 134 2 2 94 3 100 4 150 A 60 fra a A

Standard electrode potential for Cr Cr couple is 0 74 V and tha for Fe Fe couple is 0 77 V These two couples in their standar state are connected to make a cell The cell potential will be 0 81 V O 0 03 V O 1 51 V O 1 21 V

8 In the following questions calculate the final volume of gas in Litre at the specified conditions assuming the temperature and mass remain constant Ans a 0 15 L b 1 25 10 L a V 200 cm p 600 mmHg and p2 800 mmHg b V 110 m p 750 mmHg and p2 660 mmHg

Consider the given situation David was walking through a subway station that was highly crowded He took out his handgun and fired it randomly because he liked the sound made by the firing Even though David has no intent to shot anyone in the crowd the shot fired by him injured Susan David will be held liable for which type of tort a Negligence b Strict liability c Intentional tort d Recklessness nswer LA

Collision theory explains how chemical reactions occurs Using this theory and kinetic molecular model which of the following influence the rate of reaction Temperature of the system The geometry or orientation of collision The velocity of the reactants at the time of collision Concentration of reactants

5 Find value at pressure 2atm If for maximum m adsorption has a value 0 2 m If n 1 for physical adsorption 1 0 1 3 0 15 2 0 4 4 0 20 56 affiffifer X m fitur f 2 0 4 4 0 20 0 2 a 2atm afe n 1 i 1 0 1 3 0 15

View In English The boiling point of an aqueous solution of a non volatilo solute is 100 15 C What is the froozing point of an aqueous solution obtained by diluting the above solution with an equal volume of water for water Kb 0 512 Kf 186 1 4 Correct Answer 3 Your Answer 1 Status incorrect 0 544 C 0 512 C 0 272 C 1 86 C Add to Bookmark List D

The resistance of 0 0025 M solution of K SO4 is 326 ohm The specific conductance of the solution if cell constant is 4 4 1 4 997 x 10 4 2 5 997 x 10 7 3 6 997 10 4 4 1 20 x 10 as

7 If x gm of steam at 100 C is mixed with 5x gm of ice at 0 C calculate the final temperature of resulting mixture in C The heat of vaporisation and fusion are 540 cal gm and 80 cal gm respectively OFO row is availabl

13 In a period of 1 sec 5 00 x 1023 nitrogen molecules strike a wall with an area of 8 00 cm If the molecules move with a speed of 300 m s and strike the wall head on in the elastic collision determine the pressure exerted on the wall The mass of one N molecule is 4 68 10 kg Ans 17 6 KPa

the C D If the rate expression is 1 2A B r K A B and if volume is reduced to rate of reaction will increase 1 27 times 2 9 times 3 8 times 3 the

1 1 5 NA 3 1 5 10 NA 4 150 NA 68 g sample of a compound containing carbon and oxygen only contains 47 05 oxygen by mass The empirical formula of the compound is 1 CO 2 CO 3 C 0 4 C O

One mole of a real gas is subjected to a process from 2 bar 30 L 300 K to 2 bar 40 L 500 K The molar heat capacity of gas at constant volume and constant pressure are 25 and 40 J K mol respectively What is the change in internal energy of the gas in this process a 5000 J c 8000 J b 6000 J d 10 000 J

For reaction 2B Which of the following is correct 1 Rate of disappearance of B is twice that of rate of disappearance of C Medorral 2 Rate of disappearance of A is twice that of rate of disappearance of C 3 Rate of appearance of C is twice that of rate of disappearance of A 4 All of these

24 Calcium phosphide Ca P formed by reacting magnesium with excess calcium orthophosphate Ca PO was hydrolysed by excess water The evolved phosphine PH was burnt in air to yield phosphrous pentoxide P O How many gram of magnesium metaphosphate would be obtain if 192 gram Mg were used Atomic weight of Mg 24 P 31 Ca PO Mg Ca P MgO 2 Ca P H O Ca OH PH 2 PH O P O5 H O 3 2 MgO P 05 Mg PO3 motaphosphate

In the cell reaction H 2 atm H H IH p atm for spontaneous cell reaction the value of p should 1 Less than 2 atm 2 Greater than 2 atm 3 Equal to 2 atm AY Any value of pressure

The work involved w in an isothermal expansion of n moles of an ideal gas from an initial pressure of P atm to final pressure of 1 atm in number of steps such that in every step the constant external pressure exactly 1 atm less than the initial pressure of gas is maintained is given as a nRT i P 1 i P b nRT P 1 1 i 1 P 1 i i P 1 1 c nRT i

Two cylinders A and B of equal volume are connected through a hallow pipe of negligible volume that allows the transfer of gas between two cylinders if stopcock is opened Initially both are filled partially with equal volume of water and stop cock is closed Then oxygen gas is collected in A and nitrogen in B Pressure in A is 125mmHg and in B is 425mmHg What will be the net pressure if the stop cock is opened at same temperature Aqueous tension at the given temperature 25mmHg

2 A current of 0 965 ampere is passed through 500 ml of 0 2 M solution of ZnSO4 for 10 minutes The molarity of Zn after deposition of zinc is 1 0 1 M 2 0 5 M 3 0 8 M 18 4 0 194 M

14 Latent heat of vaporization of a liquid at 500 K and 1 atm pressure is 10 0 kCal mol What will be the change in internal energy of 3 mol of liquid at same temperature and pressure A 13 0 kCal C 27 0 kCal B 13 0 kCal D 27 0 kCal

4 If one mole of an ideal monoatomic gas undergoes a reversible cyclic process as given in volume versus temperature graph Volume is taken in litre and temperature is taken in kelvin V litre 16 8 B C 500 V T constant A 1000 K T K

16 The volume 80 m cylinder contains oxygen gas at a temperature of 280 K and a pressure of 300 kPa Determine the a mass of oxygen in the cylinder b the number of oxygen molecules in the cylinder c the rms of oxygen in the cylinder Ans a 320 90 kg b 6 209 x 1027 c 467 m s

4 347 s The rate of formation of a dimer in a second order dimerisation reaction is 9 1 x 10 mol L sat 0 01 mol L monomer concentration What will be the rate constant for the reaction 1 9 1 10 L mol s 2 9 1 10 L mol s 3 3x10 L mol 4 27 3 10 L mol s 67 4 347 facta fe ft facra fufen 0 01 mol L 9 1 x 10 mol L Dimer Monomer fuffer from 1 9 1 10 L mol s 2 9 1 10 L mols 3 3 10 L mol 4 27 3 10 L mol s facer chefch

A gas shows following graph at 25 C Density A B Ideal gas Amongs the following select correct option s for gas C Pressure Realgas A In the Low pressure region the gas is less compressible than ideal gas at 25 C Boyle temperature of gas must be more than 25 C Molar volume of gas is less than that of ideal molar volume at 25 C in low

A balloon is filled to a volume of 7x10 ml at a temperature of 20 degree Celsius The ball oon is then cooled at a constant pressure to a temperature of of 1 00 10 K What is the final volume of the balloon

1 A vessel of volume 22 4 dm contains 2 0 mol H and 1 0 mol N at 273 15 K Calculate a the mole fractions of each component b their partial pressures and c their total pressure Ans a 0 666 0 333 b 2 0004 1 0002

17 The equivalent conductivity of 1M H SO4 solution would be if specific conductance is 26 10 2S cm 1 1 1 3 10 S cm eq 2 1 6 10 S cm 1 3 13 S cm mol 1 4 1 3 x 10 S cm mol 1 2 1x30x5 35 5 9650

20 mL 5M NaNO2 solution is mixed with 100mL 2M HNO2 solution to prepare a buffer solution of pH 5 7 The K of HNO2 is 10 6 10 5 4 x 10 6 4 x 10 5 Marks 4 1

15 Given that the rms of a helium atom at a certain temperature is 1350 m s determine the rms of an oxygen molecule at this temperature Ans 477 36 m s 16 The volume 80 m cylinder contains oxygen gas at a temperature of 280 K and a pressure of 300 kPa Determine the a mass of oxygen in the cylinder b the number

In a solid atoms of X form ccp lattice while atoms of Y and Z respectively are present in tetrahedral and octahedral voids If all the atoms lying on one face are removed then formula of the solid will be XYZ XYZ3 O X3Y8Z3

The resistance of a cell is 250 ohm which is filled with 0 02 M Cal2 solution having cell constant 0 9 cm1 then calculate its molar conductivity B C D 90 S cm mol 1 180 S cm mol 1 30 S cm eq 120 S cm eq

4 Using the average pk value calculated in 3 calculate the pH of the pH 7 0 buffer solution that is expec after the addition of 1 0 mL of 1 0 M HCI and 1 0 mL of 1 0 M NaOH compare to the actual measured pHs after the addition of the H or OH How do these calculated p Explain your results and show your calculations PKa 6 793

The standard deviation in a method for the determination of substance a in a given sample has been found to be 0 03 ppm How many measurements should be made if the 95 confidence level z 1 96 is to be 0 017 A 12 C 13 B D 9 10

Pure water is saturated with pure solid AgCl A silver rod is placed in the solution and the potential is measured against normal calomel electrode at 25 C This experiment is then repeated with a saturated solution of Agl If the difference in potential in the two cases is 0 177 V the ratio of solubility product Kp of AgCl and Agl at the temperature of the experiment is 10 Determine the value of x 6 Ag AgCl s Calomel Saturated solution Ag Ag1 s Calomel Saturated solution Eagl M E E EAgCl Ag This can be understood as Ag Agi s AgCl s Ag Or Ag Ag aq Ag aq Ag K AgI K AgCl 0 0 177 0 059 log 1 K AgCl sp K Agl 0 177 10 Ag Ag E

If 5 ampere of current is passed through a solution for 10 hours the the number of electrons flown through the solution is Charge of electron 1 6 10 1 C O 6 02 x 1025 1 1 x 1024 O 1 8 x 106

a gle a x K A A 1 386 min C 16 min a x 1 If 0 tan 0 5 and OA 2 1 cm then the half life for this reaction is t min D B 4 min 2 min

3 2 10 atm 4 2 10 atm The volume strength is 11 2 V and density is 1 05 g mL 78 for 500 mL H O solution then what is the W W weight percentage of H O solution 1 6 69 2 6 48 3 3 35 4 3 24 If 25 ml of 0 25 M NaCl solution is diluted with 79 1 7 7 x 10 atm 3 2 10 atm 500 f H O 1 1 6 69 3 3 35 ufa 25 ml 2 0 25 2 7 7 x 10 atm 4 2 10 atm E A CIRCE HER 11 2 V H O facra ff 2 6 48 4 3 24

64 Calculate the carbonate ion concentration CO 2 in a 0 10 M solution of the weak acid carbonic acid H CO3 The dissociation constants of carbonic acid Ka 4 5 x 10 7 and Kaz 4 7 x 10 1 1 4 7 x 10 M 2 1 0 10 M 3 4 5 107 M 4 2 1 x 10 are

4 In a mixture of 13 g H 60 g of N and 3 g of NH3 calculate a number of moles of each component b mole fraction of each component and c how many molecules are present in each case Ans a 6 44 2 14 0 176 b 0 7354 0 2444 1 541 5 Determine the ratios of a the mean speeds b the mean kinetic energies of He atoms

The same amount of electric current is apassed through aqueous solution of MgSO4 and AICI3 If 2 8 g Mg metal is deposited at amount of Al metal deposited in second cell will be 1 2 1 g 2 2 49 g 3 3 15 g 4 3 73g

5 Lead II bromide is prepared using the following reaction Pb NO3 2 aq KNO3 aq unbalanced KBr aq 7 PbBr s How many milliliters of 1 25 M Lead II nitrate Pb NO3 2 are needed to prepare 150 grams of PbBr in excess potassium bromide solution Assume you have 100 yield a Fill in the stoichiometric flowchart below with the information from this problem

3 On a cold dry morning after a frost the temperature was 5 C and the partial pressure of water in the atmosphere fell to 0 30 kPa Will the frost sublime What partial pressure of water would ensure that the frost remained Ans the frost will sublime

4 Fe H O C1 3H O If relative lowering in vapour pressure is 0 5 for 90 fenfu face award sufees 2447 aqueous solution of urea then 0 5 am 1 m 0 5 2 W W 30 39 3 Xolute 1 4 M 0 5 100 1 m 0 5 W 30 2 x 100 39 W 3 Xfrm 1 AY M E

A 2 7 gm sample of pure aluminium is heated in a stream of O2 gas for some time resulting in gain in weight due to formation of Al2O3 The final weight is 4 86 gm Select correct option s Al 27 O Percent of aluminium that remains unoxidized is 90 Percent of aluminium that remains unoxidized is 10 O Percent of aluminium that is oxidized is 90 Percent of aluminium that is oxidized is 80

an organic acid Molecular mass 90 reacts with excess of silver nitrate to form a precipitate of mass 15 2 g of its silver salt On heating this precipitate 10 8 g residue is obtained The basicity of the organic acid is Ag

Five moles of an ideal gas expand isothermally and reversibly from a pressure of 10 atm to 2 atm at 300 K What is the largest mass approx which can be lifted through a height of 1 m in this expansion A 20 48 g C 20 48 kg B 204 8g D 2048 kg