Physical Chemistry Questions

A NaCl KCl mixture weighing 2 5005 g was dissolved in water and diluted to a total volume of 100 mL A 10 mL aliquot of this solution was then passed through an acid form cation exchange column It Required 28 1mL of 0 1032 M NaOH to titrate the resultant solution coming through the column Calculate the percentage of KCI and the total percentage of Cl in the mixture

2 For given half cell Al 3e Al on increasing Al the electrode potential 1 Increases 2 Decreases 3 No change he Istem n2 aid of 4 First increases then decreases

4 The equation of state for one mole of a gas is PV RT BP where B is a constant independent of temperature The internal energy of fixed amount of gas is the function of temperature only If one mole of the above gas is isothermally expanded from 12 L to 22 L at a constant external pressure of 1 bar at 400 K then the change in enthalpy of the gas is approximately B 2 L mol a 0 b 3 32 J c 332 J d 166 J

5 moles of N and 20 moles of H are allowed to react to form NH3 as the only product The correct information s is are At t 0 average molar mass of gaseous mixture 7 2 gm mol After complete reaction average molar mass of gaseous mixture 12 gm mol After 50 reaction of N gas average molecular mass of gaseous mixture 9 gm mol At any stage of reaction 90 of H may be consumed

6 A vacuum pump can generate vacuum of about 1 nTorr Assuming that air consists of N molecules with a collision diameter of 390 pm at 23 C calculate a the mean speed of the molecules b the mean free path c the collision frequency in the gas Given KT 2op z mean speed Ans a 472 02 m s b 1 45 104 m c 0 0324 sec 1

56 75 V 500 ml H O at S T P solution is kept in an open container due to which some H O2 is decomposed and evolves 8 gm O2 If 20 volume of total solution is lost due to decomposition of H O vapourisation of H O Find final volume strength of H O aq Fill your answer as sum of digits excluding decimal places till you get the single digit answer

The radius of Ag ion is 126 pm and that of I ion is 216 pm The co ordination number of Ag Sum of octahedral voids and tetrahedral voids touched by a body diagonal plane in fcc lattice Sum of hexagonal faces and equilateral triangle faces in truncated tetrahedron will be

0 An ideal gas at 650 Torr occupies a bulb of unknown volume A certain amount of gas is withdrawn and found to occupy 1 52 cm at one atmp The pressure of the gas remaining in the bulb is 600 Torr Calculate the volume of the bulb taking temperature constant 3 ent

Consider the following electrochemical cell a Write a balanced net ionic equation for the spontaneous reaction that take place in the cell b Calculte the standard cell potential E for the cell reaction c If the cell emf is 1 6 V what is the concentration of Zn d How will the cell potential be affected if KI is added to Ag half cell Zn E AD Ag 0 8 V E12 0 76 V Zn NO3 2 Salt Bridge Ag 0 1 M AgNO

If Cl and PCI can react to form PCI according to following reaction Cl PC1 PCI In tube A 355 gm Cl is taken and in tube B 1375 gm PCI is taken When half the mass of gas in tu A is transferred to B reaction look place in B After the reaction is complete half of the mass mixture in B is again transferred to A to cause same reaction in container A no reversibility Select the correct option s A Tube A contains 3 75 moles of PCI 1 25 moles of PCI finally B Tube A contains 2 5 moles of Cl 1 25 moles of PCI finally C Tube B contains 3 75 moles of PCI 1 25 moles of PCI finally D None of these 3

In a period of 1 00 s 5 00 10 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 collisions determine the pressure exerted on the wall The mass of one N molecule is 4 68 10 26 kg

If in earlier days there were not any adv ance technology then how scientists w here able to discover the different types of elements and how the were also abl e to find out the atomic number and ato mic mass of elements

3 10 4 100 How many coulomb are required for the 62 oxidation of 1 mol of H O to O 1 9 65 10 C 3 1 93 10 C Al infinite dilutions the equivalent conductances 63 3 3 10 2 93000 C 4 19 3 10 C H 0 1 9 65 10 C X 3 1 93 10 C 4 100 0 fang 2 93000 C 4 19 3 107 C

10 Copper has two naturally occurring isotopes 63 Cu and 65Cu If the average atomic mass of copper is 63 546 u then natural abundance of lighter isotope of Cu will be NCERT Pg 17 1 46 4 2 27 3

A 23 18 mL solution containing 1 769 g Mg NO is mixed with a 34 58 mL solution containing 1 432 g NaOH Calculate the concentrations of the ions remaining in solution after the reaction is complete Assume volumes are additive If a species fully precipitates type 0 Be sure your answer has the correct number of significant digits MM MNO M Na M OH 0

A vessel contains 0 25 moles of Helium and 0 15 moles of neon at 298K and 2 4 atmosphere pressure Calculate the partia pressure of each gas in the mixture 1 5 atm 0 9 atm 2 5 atm 0 9 atm 3 5 atm 1 5 atm 1 5 atm 1 5 atm Clear Response

Question No 59 Single Correct A A If 1 mole A and 4 mole B on mixing have total 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 C D A5 mix ve AHmix ve AGmix ve AVmix ve Marks 4 00 1 00 71

27 16 gm of O expand at constant pressure and 273 15 K to occupy double its original volume The work done during the process will be A w 260 cal B w 180 cal C w 130 cal D w 273 15 cal

Given Sn Sn 2e E 0 66 V Fe Fe 2e E 0 33 V Most strong oxidising agent will be 2 Sn 4 Fe 1 Sn 2 3 Fe ALLEN 64 framan Sn Sn 2c E 0 66 V Fe Fe 2e E 0 33 STTUR Ses van fasech Brit 1 Sn 3 Fe 2 Sn 4 Fe

The wave functions of 1s and 2s atomic orbitals possess Same angular radial parts Same radial part but different angular part

On titration of 5 ml 0 8 M sodium carbonate solution with 0 4N HCI 3 Column I Column II Volume of HCI added in ml A 0 B 5 C 10 D 15 For H CO3 K 10 7 K 10 P Buffer solution of HCO3 and CO Q pH 7 R pH 9 S pH 7 T OH H

For an ideal gas kept in a container attached with manometer as shown find volume of container In litres for the given gas log P vs og 1 V graph is given Density of Hg t 13 6 g ml Gas P 760 mm 76 cm liquid A d 68 g ml log P 0 4771 45 P atm V L log

Part B Using K 2 NO g N2 g O2 g 7 Initially NO 0 772 M If K 30 25 what is NO eq 8 Initially N 0 10 M and 0 0 10 M If K 0 040 find NO eq 9 NO 0 50 M and N2 i 0 030 M If K 7000 find NO eq 10 Initially NO 0 51 N 0 42 and 0 0 19 If K 0 115 what is NO eq hint calculate Q to determine which direction the reaction will proceed

When one mole of C6H5COOH s is burnt completely in sufficient oxygen in closed rigid vessel then it liberate 2kJ heat at 300K Find magnitude of enthalpy change of reaction in Joules at 300K when 12 2gm C6H5COOH s is reacted with 48 grams of oxygen R 8J mol K

For given hypothetical elementary parallel reaction K 2B A where K K 1 4 K 2 K2C nitially only 2 moles of A are present The total number of moles of A B and C at the completion of 50 of reaction O 2 3

The maximum radius of sphere that can be exactly fitted in the octahedral hole of cubical closed packing of sphere with radius r is estion Type Single Correct Type 1 0 732 r

A portion of helium gas in a vertical cylindrical container is in thermodynamic equilibrium with the surroundings The gas is confined by a movable heavy piston The piston is slowly elevated by a distance H from its equilibrium position and then kept in the elevated position long enough for the thermal equilibrium to be re established After that the container is insulated and then the piston is released After the piston comes to rest what is the new equilibrium position of the piston with respect to initial position a The piston ends up 0 4H above its initial position b The piston ends up 0 6H above its initial position c The piston ends at its initial position d The piston ends up 0 4H below its initial position

Note Magnetic quantum number also represents quantized value of z component of angular momentum of the electron in an orbital through the expression Lz m h 2 If 0 is the angle between z axis and angular momentum vector Lz L cos 0 h m 21 7 1 2 1 2 2 1 1 1 cos 0 m cos e

In an experiment to study the reaction A 2B C 2D the initial rate d A dt a t 0 was found to be 2 6 10 M s 1 What is the value of d B dt 1 2 6 x 10 3 1 3 x 10 at t 0 in M s 1 2 5 2 x 10 4 1 0 x 10 1

Determination of Ksp of sparingly soluble salts can be done by measuring conductivity of saturated solutions of the salts In one such experiment the conductivity of saturated aqueous MA solution was found to be 3 6 x 10 4 S m 1 If the conductivity of water is 6 x 10 5 S m 1 and the equivalent conductivity of M and A2 ions in this solution are 6 4 10 3 and 8 6 10 3 S m eq 1 respectively the value of Ksp of MA is 1 10 10 3 4 x 10 12 2 9 10 14 4 2 5 10 7

101 The energy functional from a trial wave function is E a a 3a 6 The variationally optimized energy is a 2 b 3 100 8 c N W is c

73 Given that Ni Ni 0 25 V Cu Cu 0 34 V Ag Ag 0 80 V Zn Zn 0 76 V Which of the following reactions under standard condition will not take place in the specified direction 1 Ni Cu Nis Cu aq 2 2Ag Cu s 2Ag s Cu2 2 3 Zn Cu ALLEN 73 Cu s fe Ni Ni 0 25 V Cu Cu 0 34 V Ag Ag 0 80 V Zn Zn 0 76V f fuff sta 1 N4 Cu s 2 2Ag Cu aq 3 Zn Cu aq Nis Cu 2Ag Cut Cu s 11 aq Zn

Consider how to prepare a buffer solution with pH 3 47 using one of the weak acid conjugate base systems shown here by combining 1 00 L of a 0 304 M solation of weak acid with 0 363 M sodium hydroxide Weak Acid HNO HCIO HCN Conjugate Base NO CIO CON K 4 5 x 104 3 5x108 4 0x 10 10 pk 3 35 7 46 9 40 How many L of the sodium hydroxide solution would have to be added to the acid solution of your choice

Using R calculate Kendall s tau and the Pearson s correlation coefficient between Weight and Sodium in Data and test whether each is different from 0 at a 0 05 What is the p value for Kendall s tau Answer in the exact form in R e g 0 00e 00 What is the p value for the Pearson s correlation coefficient Answer in the exact form in R e g 0 00e 00

28 If the density of copper is 8 94 g cm the number of Faradays required to plate an area 10cm x 10cm of thickness of 10 2 cm using CuSO solution as electrolyte is 2 0 28 F 4 0 5 F 1 0 1 F 3 0 4 F

In this experiment you will quantitatively measure a reaction rate of S O2 with I in solution to produce 1 according to the following reaction slow S 0 21 1 2504 The color change is very sudden and dramatic when 2x10 mol of Iz is produced The time required to produce 2x10 mol of l can be measured accurately 1 Write the rate expression for the reaction 2 Write the rate law for the reaction

Use the basic facts to add hundreds 1 5 2 5 hundreds 2 hundreds 500 200 2 4 5 4 hundreds 5 hundreds 400 500 3 2 6 2 hundreds 6 hundreds 200 600 hundreds hundreds hundreds 4 If you add 2 to me I will become 3 less than 40 W

A 2 5 g impure sample containing weak monoacidic base Mol wt 45 u is dissolved in 100 mL water and titrated with 0 5 M HCI When 1 4 th of the base was neutralised the pH was found to be 9 and at equivalence point pH of solution is 4 5 Select correct statement s A K of base is less than 10 6 B Concentration of salt C at equivalent point is 0 25 M C Volume of HCI used at equivalent point is 100 mL D Weight percentage of a base in given sample is 80

Problem On a humid day in summer the mole fraction of gaseous H O water vapor in the air at 25 C can be as high as 0 0287 Assuming a total pressure of 0 977 atm what is the partial pressure in atm of H O in the air

In a closed vessel of 15 litres 5 6 litres of water gas at STP containing equimolar amount of both the constituent gases is ignited with 5 6 L of O2 at STP What will be the approximate final pressure of the vessel at 300 K

2 7 A vessel of volume V 301 is sepa rated into three equal parts by stationary semipermeable thin particles Fig 61 The H2 Fig 61 02 N 2 left middle and right parts are filled with mH 30 g of hydrogen mo 160 g of oxygen and mN 70 g of nitrogen respec tively The left partition lets through only hydrogen while the right partition lets through hydrogen and nitrogen What will be the pressure in each part of the vessel after the equilibrium has been set in if the vessel is kept at a constant TEO

Initially the r m s speed of an atom of a monatomic ideal gas is 250 m s The pressure and volume of the gas are each doubled while the number of moles of the gas is kept constant Calculate the final translational r m s speed of the atoms

3 Given that the r m s of a helium atom at a certain temperature is 1350 m s determine the r m s speed of an oxygen 0 molecule at this temperature The molar mass of O is 32 0 g mol and the molar mass of He is 4 00 g mol 2

In an ionic compound anions form hcp arrangement and cations present at all the tetrahedral voids It radius of cation rc 25 pm radius of anion ra 75 pm then select the correct statement s Simple formula of compound is A B where A is cation and B is anion Simple formula of compound is AB where A is cation and B is anion Closest distance between two anions is 150 pm Closest distance between two anions is 100 L813 pm

An amount of 20 Ci of 32P TR 14 3 d is injected into the bloodstream of a reference adult m 70 kg 32p is metabolized in such a way that 40 is uniformly distributed throughout the whole body where it is cleared with a biological half life of 19 d What is the effective half life of 32P in the total body O A 19 d OB OC 8 16 d 3 26 d O D 14 3 d

1L Mixture of 0 1M CH COOH 0 01M CH COO correct log 5 0 7 log 7 0 9 pH of the given solution is 4 Ca pH of the given solution is 3 7 is taken If K CH COOH 2x10 5 a which of the following statements are There is an increase in pH by 0 9 when 0 05 moles of NaOH is added to the 1L of the given solution There is an increase in pH by 0 3 when 0 05 moles of NaOH is added to 11 of the given solution

3 3 Zn Cu 4 2H aq Zn s H2 g If the specific conductance and conductance of a 74 solution are same then its cell constant is equal to 2 0 3 10 4 100 Zn Cu s aq 2 3 Zn Cu Zn Cu s aq H2 g 2 aq 4 2H Zn s aq fastfera un fafing art fra andre fontes 1 1 2 0 Zn aq 3 10 4 100

Jeans 100 ml each of 0 5 N NaOH HC and N 5 H SO are mixed together The resulting solution will be 1 Acidic 3 Alkaline 2 Neutral 4 None of these huslast Leader Achiever Course ALL PHASE 68 N N H SO 10 100 ml fra fan arant at utrum fara vefat 0 5 N NaOH HC 5 1 3 a 2 Jarfa 4 1001CMD303119105 40003

20 Out of the following incorrect statement s is are A Cv is independent of T for a perfect gas A process in which final temperature equals initial temperature must be an isothermal process e AT 0 for every adiabatic process in a closed system D All of these B foot gas at

43 When completely protonated form of glycine is titrated with NaOH which of the following represents the pH Vs conc NaOH plot Chemical formula of glycine is H NCH COOH pH B A C pH pH NaOH added NaOH added D pH NaOH added NaOH added