Physical Chemistry Questions

If the oxidation state of the central atom is in an intermediate value it will act as 1 Oxidising agent only 2 Reducing agent only 3 Both oxidant and reductant 4 Cannot be predicted 0 1 O 2

Select the correct statement s based on following graph at constant pressure for an ideal liquid binary solution B is more volatile than A 100 A Gas Pure A can be obtained in final distillate liquid Composition 100 B Vapour pressure of solution will be 160 mm Hg if it contain 20 A by moles PO 200 mm Hg P 150 mm Hg A Boiling point of the mixture is always in between boiling points of pure A pure B

28 Under the same condition heats of formation of 2 water CO are 285 and 394 kJ mol respectively The heat of combustion of methane is 890 kJ mol 1 The heat of formation of methane in kJ mol is 1 964 3 222 2 890 4 74

Consider an irreversible reaction A B C with a rate law R K A n B m d If B o were 2 mmol L t s A x 10 mol L B x 10 mol L 0 2 2 What would be the overall order of the reaction 1 10 1 1 20 1 2 1 2 What would be the order of the reaction with respect to A Unknown What would be the order of the reaction with respect to B Unknown 30 1 4 1 4

Which of the following is not concerned to effective nuclear charge X 1 Higher ionization potential of carbon than boron 2 Higher ionization potential of magnesium than Aluminium 3 Higher values of successive ionization energy 4 Higher electronegativity of higher oxidation state

The enthalpy of formation of ethane ethylene and benzene from the gaseous atoms are 2839 2 2275 2 and 5506 kJmol respectively Calculate the resonance energy of benzene The bond enthalpy of C H bond is given as equal to 410 87 kJ mol A 80 68 kJ mol B 23 68 kJ mol C 96 68 kJ mol D 46 68 kJ mol

a Determine the normal boiling point of benzene C6H6 given that its vapour pressure is 20 0 kPa at 35 C and 50 0 kPa at 58 8 C b When 12 2 g nonvolatile compound is dissolved in 54 g of benzene at 58 8 0 C the vapor pressure fell to 45 kPa Calculate the molar mass of the compound pression

16 When AH and TAS both are negative then for spontaneous process which option is true 1 AH TAS 2 AH TAS X 3 AH TAS 4 AH AU Offion Ankach Tower 8 Pusa Road New Delhi 110

Match the oxide given in Column A with its chemical nature given in Column B Column A a NO b AS203 c SO3 d Na O Column B i Acidic ii Basic iii Neutral iv Amphoteric

What is the calculated value of the cell potential at 298K for an electrochemical cell with the following reaction when the pressure is 1 20 atm the F concentration is 7 59 10 3M and the Cd2 concentration is 6 72x10 M F2 g Cd s 2F aq Cd aq Answer V The cell reaction as written above is spontaneous for the concentrations given

Regarding non ideal behaviour of gases choose the correct statements Gas which behave ideally over a large range of pressure at Boyle s temperature is easy to liquify Vanderwaal constant b is larger for Ar than Ne gas The value of Boyle s temperature increases with the strength of attractive interaction between molecules Pressure exerted by 1 mole O is greater than 1 mole H O at 350K if both gases are present in same volume

A certain ideal gas whose R 278 6J kg K and cp 1 015 KJ kg K expand isentropically from 1517 kPa 288 C to 965 kPa For 454 g s of this gas determine a WNE b V2 c Delta U and g Delta U With Derivation of Formulas A certain ideal gas whose R 278 6 J kg K and cp 1 015 KJ kg K expand isentropically from 1517 kPa 288 C to 965 kPa For 454 g s of this gas determine a WNF b V c AU and g AU T LJ

The gas phase reaction 2 A B C is biomolecular with an activation energy of 24 000 cal mol The molecular weight and diameter of A are respectively 60 and 35 A Calculate from kinetic theory the specific rate constant for decomposition at 27 C

The equilibrium constant of the reaction at 25 C CuSO4 5H O s CuSO4 3H O 2H O g is 1 084 10 4 atm Find out the relative humidity CuSO4 5H O will start loosing its water of crystalliziation according to above reaction Vapour pressure of water at 25 C is 24 mm of Ha

Estimate the mass of water that must evaporate from the skin to cool the body by 0 55 C Assume a body mass of 100 kg and assume that the specific heat capacity of the body is 4 0 J g C Express your answer using two significant figures VAXO 1500

Determine the mass in grams of oxygen obtained when 567 mL gas was collected over water at 1 402 atm and 85 0 C The vapour pressure of water is 433 6 mmHg at 85 0 C 2 Ag2O s 4 Ag s O g You must use the values of the constants and any conversions given on the Exam 4 Periodic Tables and Constants Attachment If you use any other source that gives you an imprecise or incorrect answer you may not receive credit for the question Your Answer

28 A student wishes to make an electrochemical cell with Ecell 1 0645 V based on 2 Zn s Zn aq Cu aq Cu s at 298 K for which Ecell 1 1030 V If both metal ion solutions are initially of equal molarity which solution needs to be decreased in concentration and by what factor to produce a cell with Ecen 1 0645 V

Compared to chlorine gas Cl2 MW 70 9 the average speed of a carbon monoxide molecule CO MW 28 0 is a 2 5 times faster d 2 5 times slower b 1 6 times faster 1 6 times slower c 0 63 times faster f 0 63 times slower

570 g of potassium thiosulphate K S O3 reacts with copper sulphate to form cupric thiosulphate which is reduced by remaining potassium thiosulphate to give cuprous compound which reacts with the remaining potassium thiosulphate to form a complex compound potassium cuprothiosulphate K Cu S 03 GUSO K S O CuS 0 K SO4 2CuS O3 K S O3 Cu S O3 K S406 3C0 S 0 2K S O3 KlCue S 03 5 potassium cuprothiosulphate In this process 02 mole of potassium cuprothiosulphate is formed O 16 K 39 S 32 If instead of given amount of potassium thiosulphate 2 moles of potassium thiosulphate along with 3 moles of CUSO were taken initially then moles of potassium cuprothiosulphate formed a

During electrolysis 4828 4 mg of iodine requires 3671 3 coulombs of electricity for its deposition at the anode Calculate the value of Faraday s constant Ans 96489 25 C na

30 A special gas mixture used in bacterial growt chamber contains 1 by weight of CO and 99 of O What is the partial pressure in atm of eac gas at a total pressure of 0 977 atm 1 Po 0 970 atm Pco 0 1 atm 2 Po 0 970 atm Pco 0 00711 atm 3 Po 0 1atm Pco 0 9 atm 4 Can t predict

16 Chlorophyll the green pigment in plants has the molecular formula C55H72MgN4O5 If 0 012 g of Mg is available to a plant for chlorophyll synthesis how many grams of carbon will be required to completely use up the magnesium C 12 H 1 Mg 12 N 14 O 16 1 0 33 g 2 0 66 g 4 1 35 g 3 0 99 a

1 In an experiment 2 moles of HI are taken in an evacuated 5 0 litre container At 144 C the equilibrium constant is equal to 0 0156 for the gaseous reaction 2HI g H g I g Calculate the equilibrium concentrations of HI H and I

Enthalpy changes for two reactions are given b the equation 3 2Cr s O g 2 C s O g The enthalpy Cr O3 3C 1 1460 kJ 3 800 kJ Cr O3 s AH 1130 kJ CO g AH 110 kJ change for the reactio 2Cr 3CO will be 2 800 kJ 4 1020 kJ

One mole of Na2SO4 10H 0 is dissolved in 820 grams of water to make a solution What is the molality of Na ions in the resulting solution Atomic mass u H 1 0 16 Na 23 S 32 Only One Correct Answer A More than 2 molal B C Equal to 2 molal Less than 2 molal i

Question 38 For a zero order kinetics 2AP the initial concentration of reactant given is 0 05M The variation of degree of dissociation with time is denoted by the following graph a 8 time Using graph calculate value of rate constant x degree of dissociation tan 0 5 Initially only A is present A 0 125 B 0 0125 c 1 25 12 5

Let s say you re a diver and want to use an oxygen tank to breath under water At 250 ft the P 02 8 38 atm and the P 02 in the tank is 0 21 atm the same as it is in the air we breath at 1 atm normally What is the mole of oxygen in the tank Start by writing the equation that you ll use to solve the problem 1 2 4 6 8 9 2 5

4 Na SO is added in water to make 12 w w solution having density 1 2 g mL Correct statement for resulting solution is are a Nearly 0 96 mole of Na SO4 dissolved per kg of H O b Normality of Na ion is equals to normality of so ion c Molarity of solution is less than molality 1 a b 2 b only 3 c only 4 a only

Two rods A and B of same cross sectional area A and length t connected in series between a source T 100 C and a sink T 0 C as shown in figure The rod is laterally insulated B K If TA and Te are the temperature drop across the rod A and B then TA 1 3 TB T T 100 C A 3K f f T 0 C B

570 g of potassium thiosulphate K SO reacts with copper sulphate to form cupric thiosulphate which is reduced by remaining potassium thiosulphate to give cuprous compound which reacts with the remaining potassium thiosulphate to form a complex compound potassium cuprothiosulphate K Cus S 03 s GuSO4 K S O CuS O3 K SO 2CuS O3 K S O3 Cu S O3 K SO 30u S O3 2K S O3 KalCus S 03 s potassium cuprothiosulphate In this process 0 2 mole of potassium cuprothiosulphate is formed O 16 K 39 S 32 Total moles of potassium thiosulphate reacted in the reactions is

An electric current is passed through two electrolytic cells connected in series one containing AgNO3 aq and other H SO4 ag WH volume of O measured at STP would be liberated from H SO4 if 1 mole of Ag are deposited from AgNO3 solution A 5 6 L B 2 8 L c 11 2 L 22 4 L

Question 7 It was determined that 63 5 kJ of heat is needed to vaporize enough aniline CH NH liquid at its normal boiling point of 184 C to produce 45 0 L of aniline vapor at the normal atmospheric pressure of 1 atm Calculate the enthalpy of vaporization of aniline in kJ mol You must show every step of the calculation Hint you may need to use the ideal gas law to solve this problem 4 points

1 CH3COOC H5 H O CH3COOH C H5OH 2 203 30 NH H Decomposition of NH on platinum catalyst surface dil H SO4 2H0

P 1 The enthalpy of reaction is maximum in which of the following reaction 1 NaOH HCl NaCl H O 2 NaOH HF NaF H O 3 NaOH HBr NaBr H O 4 All have same value In case of electronegativity will be high a enthalpy of react

If energy required to dissociate 16 g of gaseo hydrogen into free atoms is 3488 kJ at 25 C th the bond energy of H H bond will be NCERT Pg 17 1 384 kJ mol 3 384 1 mol 2 436 kJ mol 4 436 J mol

For a zero order reaction time taken for 75 completion of the reaction is x times the half life and for a first order reaction time taken 75 completion of the reaction is y times the half life Similarly for second order reaction time taken for 75 completion of the reaction z times the half life Value of 2x y z is z is

What volume in milliliters of H g at STP will be produced from the reaction of 50 0 mL of 12 0 M HNO3 with excess tin according to the following equation Sn s 2HNO3 aq Sn NO3 2 aq H2 g 1 34 x 10 mL 6 72 x 10 mL none of these 13 4 mL 6 72 mL

NH HS s NH g H S g Above reaction attains equilibrium at 20 C and 6 atm pressure Choose correct statements regarding the reaction The partial pressure of NH3 is higher than that of H S The equilibrium constant Kp 9 atm Kp Ko Removal of NH3 increases the yield of H S

Which of the following statement is correct 1 Entropy of egg decreases on boiling 2 Entropy of rubber band decreases on stretching 3 Entropy decreases during fusion of ice 4 All of these

71 The number of molecules with energy greater than the threshold energy for a reac tion increases five fold by a rise of temperature from 27 C to 42 C Its energy of activation in J mol is Take In5 1 6094 R 8 314 J mol

hydrogen 4 20 litres ammonia 25 litres nitrogen 15 litres hydrogen tres 50 If the weight oxygen the e 42 The maximum number of molecules is present in 1 15 L of water at STP 2 15 L of H O gas at STP 3 15 g of ice 4 Same in all 43 Concentrated aqueous sulphuric acid is 98 H SO4 w v and has a density of 1 80 gmL Molarity of solution 8x y 1 E 3 E 1 2 8 51 The numbe 1 8 3 7 52 Mole frac NaOH is

ect the correct statement s All electromagnetic radiation travel with speed of light in vacuum O Energy of photon of UV light is lower than that of yellow light Atomic spectrum is discontinuous spectrum The total energy of an electron in H like atom is greater than zero

20 Match List I Equations with List II Type of process and select the correct option List l Equations a K Q b AGO RT In Q c K Q d T 101 AH AS m List II Type of process AIPMT Mains 2010 1 a i b ii c iii d iv 2 a iii b iv c ii d i CORY i Non spontaneous ii Equilibrium iii Spontaneous and endothermic iv Spontaneous

Question 40 The specific conductivity of sparingly soluble salt AB ag at 298 K is 1 26 x 106 S cm and molar conductivity of Aa and Baq at infinite dilution are 62 Scm mol and 64 Scm mol respectively Solubility product Kp of salt AB is A 10 5 B 108 c 10 10 OD 10 16

Carbon forms two oxides namely carbon monoxide and carbon dioxide The equivalent mass of which element remains constant b of a Carbon b oxygen d neither carbon nor oxygen c both carbon and oxygen

In permanganate titrations potassium permanganate is used as an oxidizing agent in acidic medium The medium is maintained acidic by the use of dilute sulphuric acid Potassium permanganate acts as self indicator The potential equation when potassium permanganate acts as an oxidizing agent is 2KMnO4 3H SO4 K SO4 2MnSO4 3H O 5 0 or MnO4 8H 5e Mn 4H O Before the end point the solution remains colourless but after the equivalence point only one extra drop of KMnO4 solution imparts pink colour i e appearance of pink colour indicates end point These titrations are used for estimation of ferrous salts oxalic acid oxalates hydrogen peroxide As O3 etc For decolourization of 1 mol of KMnO4 the number of moles of H C O4 required is

The correct increasing order of the oxidation state of sulphur in the anions 14 50 250 2 0 2 20 2 is SC a SO2 SO S 0 S 0 2 c S O2 SO3 S O SO 2 3 b SO 2 S 02 S 0 so d S 0 S 0 SO SO 2 C 1 74

400 gm of ice at 20 C is mixed with 400 gm water at 50 C then which of the following statement s is are correct Specific heat capacity value for ice and water are s ice 0 5 cal g C S water i One More Correct Answer s A B 1 cal g C and Lfusion C D Final weight of ice is 200 gm ice Final temperature of the mixture is less than 0 C Final weight of water is 600 gm 80 cal gm Weight of ice converted into water is 200 gm

d A sample of water is found to be contain following dissolving salt in mg L Name of hardness causing salt Mg HCO CaCl Ca HCO MgSO MgCl NaCl FeSO Total Ten and Permanent Amount of hardness causing salts mg L 7 3 11 1 8 1 4 0 9 5 10 5

1 For an ideal binary solution A and B YA is the mole fraction of A in vapour phase Which of the following plot should be linear 1 PTotalVS YA 3 P 1 VS YA 2 PTotalVS YB 1 Vs VB YA PTotal 4