Physical Chemistry Questions

A bottle of sparkling wine contains carbon dioxide at a pressure of 4 0 atm The solubility of carbon dioxide at 4 0 atm is 0 15 M When the bottle is opened the partial pressure of carbon dioxide drops to 4 0 x 104 atm Determine the solubility in M of carbon dioxide in wine at this pressure

3 III II V IV I 4 V III II IV I 1 cc of 0 1 M HCI is added to 999 cc solution of 0 1 N NaCl The pH of resulting solution will be 1 7 3 2 2 4 4 1 76 2 V IV I 3 III II V IV I 4 V III N 1 1 cc 0 1 M HCI face 1 7 3 2 999 cc 0 1 N pl and a

9 4 1 0 A 5 solution of anhydrous CaCl at 0 C developed 15 atm osmotic pressure What is the degree of dissociation of CaCl A 22 33 C 21 33 A A B 24 33 D 25 33

At the equilibrium of the reaction X N O4 g 2 NO g MA Mo n 1 the observed molecular weight of N O4 is 80 g mol at 350 K The percentage of dissociation of N O4 g at 350 K is B 15 D 18 A 10 20 92 80 80 2 8 80

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

4 3 K CoCl 4 Na Ni CN 135 The solubility product of BaSO at 20 C is 1 x 10 What would be the concentration of H SO necessary to precipitate BaSO from a solution of 0 01MBa ions 1 10 2 10 3 107 4 10 2 K NICI 3 K CoCl 4 Na Ni CN 135 25 C fac Baso a fact 1 x 10 10 0 Baso fo H SO HD 1 10 3 10 2 10 8 4 10

alculations A student neglected to keep the end of the delivery tube under the surface of the water displaced by hydrogen while the collected gas was cooling What effect will this have on the volume of hydrogen collected What effect will this have on the calculated mass of magnesium

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

3 N O 4 N O The molal elevation constant of water is 0 51 Km The boiling point of 0 1 molal aqueous NaCl solution is nearly 1 100 05 C 2 100 1 C 3 100 2 C 4 101 0 C 81 3 N 0 4 N O fis 0 51 Km 10 1 NaCl a face an am 1 100 05 C 2 100 1 C 3 100 2 C 4 101 0 C

e What is photoelectric effect Draw a plot of kinetic energy for the ejected photoelectron vs frequency of the incident radiation in a photoelectric experiment with three different metals What inference regarding physical quantities may be drawn from the plot 1 3 4

2 d State Heisenberg uncertainty principle What is the uncertainty in the position of a bullet of 4 gm that is known to have a speed between 380 0001 m s and 380 0000 m s 1 2 3

2 A system has 50 000 molecules at enery level 1 10 000 molecules at energy level 2 and 500 molecules at energy level 5 What is the energetic entropy of the system What is the energetic mutliplicity of the system

27 If three forces 10 N 20 N and 10 N act at a point and angle between the first two orces is 30 and angle between the latter two forces is 60 then calculate the value of he resultant force a 33 85 N b 5 77 N c 8 66 N d 10 N

blz explain this the given answer was 6 Out of following how many mixtures are buffers solution i NaCN 0 5 mole ii NaCN 0 5 moles HCN 0 5 moles iii NH3 1 mole NH4Cl 1 mole iv CH3COOH 1 mole NaOH 0 75 moles v NH4Cl 1 mole NaOH 0 75 moles vi CH3COONa 0 5 moles HCI 0 25 mole vii H CO3 1 mole NaOH 1 5 moles

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

In general maximum difference in electronegativities is observed when we move A from second to third period B from third to fourth period C from fourth to fifth period D from fifth to sixth period

According to Freundlich adsorption isotherm at high pressure the value of 2 Inversely proportional to pressure 1 Directly proportional to pressure 3 Directly proportional to square of pressure 4 Independent of pressure 18 m

All 3 Correct 4 1 0 A 250g mol C 350g mol Incorrect A solution containing 10g per dm of urea molecular mass 60g mol is isotonic with a 5 solution of a non volatile solute The molecular mass of this non volatile solute is A A Skip B 300g mol 4 200g mol

of react reaction A 2B Calculate AG in kJ mol for the reaction 1 A B 2 Standard molar enthalpy of combustion of glucose is 2880 kJ If only 25 of energy is available for muscular work and 10 km walk consumes 90 kJ of energy what maximum distance in km a person can walk after eating 90 g of glucose Given C H g H g C H g AH 175 kJ mol 201 3 C 2 AHC Hz 50 kJ mol AHHOD 280 kJ mol AH co 390 kJ mol f C H4 2 fAH is enthalpy of combustion in kJ mol of C H g then calculate the value of AH 257 rol ontholning of solution of anhydrous CuSO s and hydrated CuSO4 5H O s are

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

Kinetics of Nuclear Decay The activity of the radioactive sample drops to 1 64 of its original value in 2 hr find the decay co

Vapour pressure of pure water at 25 C is 80 torr and that of an aqueous solution is 75 torr at the same temperature If K for water is 1 86K kg mol then freezing point of the solution is O 6 48 C 6 88 C O 6 99 C O 6 27 C

31 Two reactions of the same order have equal pre exponential factors but their activation energies differ by 24 9 kJ mol Calculate the ratio between the rate constant of these reactions at 27 C Gas constant R 8 3 JK mol

What is the 3rd half life of the second order decomposition of a compound given that its first half life is 20 s 1 20 s 3 80 s In the reaction 2 40 s 4 84 s 6 6

Q 32 Compressibility factor Z of a gas is given as Z pV nRT i What is the value of Z for an ideal gas ii For real gas what will be the effect on value of Z above Boyle temperature Ans i For ideal gas compressibility factor Z 1 ii Above Boyle s temperature real gases show positive deviation Z 10 emulov So 9191020 15

arranged shown in Fig 1 10 Fig 1 10 Packing of Nat and Ct ions in sodium chloride It may be noted that in sodium chloride one Nat is surrounded by six CI and vice versa The formula such as NaCl is used to calculate the formula mass instead of molecular mass as in the solid state sodium chloride does not exist as a single entity Thus formula mass of sodium chloride atomic mass of sodium atomic mass of chlorine 23 0 u 35 5 58 5

25 Maximum number of electrons in a subshell of an atom is determined by the following a 2 1 b 4 2 c 2n d 4 2 2009 Which of the following is not permissible 31 Give Plan unce velo a

Which option is correct when Cl2 reacts with excess of F2 Max score 1 Neg score 0 CIF5 is formed and the oxidation state of F is 3 and that of Cl is 1 FCl3 is formed and the oxidation state of F is 1 and that of Cl is 3 CIF3 is formed and the oxidation state of F is 1 and that of Cl is 3 CIF3 and FCl3 are formed

Which of the following is are correct statements A Particles of every matter is very very small B Particles of matter have spaces or gaps between them C Universe is made up of matter and energy D Anything which has capacity to do work is called matter

c 3 4 nm 39 Isoelectronic species are a CO CN NO C b CO CN NO C c CO CN NO C d CO CN NO C 0 TL 2000 tointu in momentum of an electron V 48 L

10 The uncertainty in momentum of an electron is 1 x 10 5 kg m s The uncertainty in its position will be h 6 62 10 34 kg m s a 5 27 10 30 m b 1 05 10 26 m d 5 25 x 10 28 c 1 05 x 10 28 m m 1999

20 mL of CO was mixed with 50 mL of oxygen and the mixture was exploded On cooling the resulting mixture was shaken with KOH Find the volume of the gas that is left

26 54 Select the correct statements regarding colligative properties of deal aqueous solutions Colligative properties are driven by entropy factor Colligative properties increases with mole fraction of water Colligative properties are independent of amount of the solution Colligative properties are independent of degree on ionization of the solute dissolved in water

4 2 at 25 C k 2 5 min k 5 5min k3 10 8 min and k 4 7 min The Arrhenius factor is 10 min for each reaction then OAB is an endothermic process BC is an endothermic process Activation energy for the conversion BA is higher than the activation energy for the conversion BC Overall order of the reaction is 1

A sample containting large number of Li2 ions all in a particular excited state is subjected a photons coming from M shell to K shell transition of any unielectronic species If the samp is further excited to a higher level de excites back to the ground state then calculate energ of the photon eV having 8th highest energy among all emitted from de excitation

2 VOSO 3 Na VO4 4 V H O JSO H O How many gram of KCI would have to be dissolved in 60 g H O to give 20 by weight of solution 1 1 5 g 2 15 g 3 25 g 4 V H O JSO H O 20 fe 4 12 g 2 VOSO 3 Na VO 86 KCI 1 1 5 g 3 25 g 2 15 g 4 12 g

In Bohr series of lines of hydrogen spectrum the third line from the red end corresponds to which one of the following inter orbit jumps of the electron for Bohr s orbits in an atom of hydrogen 1 32 2 5 2 3 4 1 4 2 5

Q 35 54 0 2 M NaOH was gradually added to 200 mL 0 1 M HCI solution After complete neutralisation of the HCI addition of NaOH was stopped and 1 7 L of water was further added to dilute the final mixture What would be osmotic pressure in atm of the diluted mixture at 35 C Given that degree of dissociation of NaCl is 98 in water Take R 0 0821 atm L mol L Answer

44 The position of both an electron and a helium atom is known within 1 0 nm Further the momentum of the electron is known within 5 0 10 26 kg m s The minimum uncertainty in the measurement of the momentum of the helium atom is a 8 0 10 26 b 80 kg m s kg m s c 50 kg m s d 5 0 10 26 kg m s The ion that is igno 1998 52 53

c Hund d ommerfield 1999 42 The de Broglie wavelength of a particle with mass 1 g and velocity 100 m s is a 6 63 10 35 m c 6 63 10 33 m b 6 63 10 34 m d 6 65 10 35 m 1999 43 The Bohr orbit radius for the hydrogen atom number 3 a 0 53 c 0 17 50 For which o quantum num highest energ 1 2 n a 3

Q 34 54 First order gas phase thermal decomposition of N O5 occur as follows N O g 2NO g 0 8 If total pressure varies with time as given in the figure then half life of the reaction is in minutes Take log102 0 30 log10 5 0 70 380 Potal 200 torr 0 100 min time

Cadmium oxide crystallizes in an NaCl type of crystal lattice The compound is however usually non stoichiometric with approximate formula CdO0 95 The defect arising due to some cationic positions are occupied by neutral Cd atom instead of Cd ions and equivalent numbers of anion sites are vacant a What percentage of anion sites are vacant b If the edge length of the unit cell is 470 pm what would be the density of perfect solid c What is the density of non stoichiometric solid

Mock Test 4 for NE 130 If 0 1 g atom of magnesium is allowed to react with 2 g 130 Mg0 1 con molecule of oxygen then which of the following is correct faff for an for given equation 2 Mg s O g 2 MgO s 1 Oxygen is the limiting reagent 2 Magnesium is the limiting reagent 3 0 02 moles of magnesium oxide are formed 4 0 5 mole of oxygen remain in excess 31 Calculate the molecular weight of a substance which fo Fin 2 Mg s O g 2 MgO s Biftet i 1 f fefta 1 2 14 3 0 02 4 30 5

66 gm sample of an oxalate salt AlxHy C O4 z nH O is dissolved in water to from 500 ml solution 50 ml solution requires 60 ml 0 5 M Ba OH 2 and 240 ml 0 1 M KMnO4 in acidic medium separately If in salt x y z n are present in simplest ratio Then select the correct statement s O Moles of oxalate salt in original sample is 0 2 O Ratio of y z is equal to 1 O Value of x y z n 5 O Number of oxalate ions per molecule of oxalate salt is 2

m For the adsorption of a substance M from aqueous solution by charcoal at room temperature the Freundlich constants are n 3 and k 0 5 for in g g and C in g l What is the weight in g of M that will be adsorbed by 2 g of charcoal from 1 litre of solution containing 2 g of the substance originally Report your answer to the nearest integer

In which of the following reaction H O acts as reducing agent I H O 2H 2e 2H O II H O 2e O 2H III H O 2e 2 OH IV H O 2OH 2e O 2H O Options are 1 I and II 2 III and IV 3 I and III 4 II and IV 79

14 Consider the column I and II Column I P NH excess Cl Q Ca OH Cl Slaked lime R NaOH Cl Conc S NH Cl excess Correct option is P 1 1 2 1 3 4 4 4 Q 4 4 2 1 Column II 1 NC3 2 oc 3 CIO 3 4 R 3 M 2 3 2 S233 1 114 4 5 P NE Q C SI R Na Co S NH Fra fa P 1 1 2 1 3 4 Car

EXAMPLE 42 The rate of reaction doubles when its temperature changes from 300 K to 310 K Activation energy of such a reaction will be R 8 314 J K mol and log 2 0 301 a 48 6 K J mol b 58 5 kJ mol c 60 5 kJ mol d 53 6 kJ mol I I T mains 2013

A sample of air containing 20 O2 and 80 N2 is dissolved in water when total pressure of air is 1 atm The solubility of N2 and O2 in terms of mole fraction is x and y This sample is taken at a height of H above sea level where pressure of air is 0 4 atm and temperature is 300 K and solubility of N2 and O2 in terms of mole fraction is x and y Assume that value of Henry s constant remains same at sea level and H The value of XY IS x y

Q 12 Hall H roult process is the major industrial process for manufacture of which metal and at what temperature Max score 1 Neg score 0 Aluminum 950 C Iron 880 C Copper Aluminum 740 C