General Questions and Answers

Suppose you have taken a dilute solution of oleic acid in such a way that its concentration becomes 0 01 cm of oleic acid per cm of the solution Then you make a thin film of this solution monomolecular thickness of area 4 cm by considering 100 spherical drops of radius 3 40m Where x is 10 3 cm Then the thickness of oleic acid layer will be xx10 14 m

A balloon weighing 50 kg is filled with 1 00 000 moles of Helium gas at 1 atm pressure and 25 C What will be its pay load if it displaces equal mo ambient air Atomic weight of He 4 Avearge atomic weight of ambient air 30 Pay load Weight of air displaced Total weight of balloon A 2550 kg B 3000 kg c 450 kg

5 A solution is prepared by adding 2 g of a substance A to 18 g of water Calculate the ma per cent of the solute Ans 10 6 56 g of Nitrogen reacts with 22 g of hydrogen to form ammonia Find 1 The limiting reagent of the reaction 2 The amount of reactant in excess 3 The amount of ammonia formed 7 Convert the following numbers in scientific notation 1 0 30054 2 5604 3 0 00000045

A 2 0 g sample of a mixture containing sodium carbonate sodium bicarbonate and sodium sulphate is gently heated till the evolution of CO ceases The volume of CO2 at 750 mm Hg pressure and at 298 K is measured to be 123 9 mL A 1 5 g of the same sample requires 150 mL of M 10 HCI for complete neutralization Calculate the percentage composition of Na SO4 in the original mixture

1 SiO CH MgBr CO 1 Ethyl acetate 2 KO Dry ether Y 3 BaO H O Z identify Z from the following 2 Acetic acid 3 Propanoic acid 4 Cs0 4 Methyl acetate pantanal on rogation with aluminium fortiory butoxide in the racon of goatona given

20 The value of equilibrium constant of a reaction changes with change of temperature and the change is given AH AH P dT RT2 where enthalpy change AH is taken as constant in the small temperature range by van t Hoff equation dln K dT If for reaction A 3B 2C a plot of In K eq versus for 1 T a reaction is shown then which of the following condition will be favourable for formation of product C C Keq 1 T a Low temperature and high pressure b High temperature and high pressure High temperature and low pressure

d All of these 6 In one of the following reactions HNO does not behave as an oxidising agent identify it a I 10 HNO 2 HIO 10NO 4H O b 3Cu 8 HNO 3Cu NO3 2NO 4H O c 4Zn 10HNO 4Zn NO NH NO 3H O d 2HNO P O 2HPO N O 7 The equivalent weight of Mu

16 k for the reaction 2 BaO 2 BaO O g is s s 1 6 10 atm at 400 C Heat of reaction is 25 14 kcal What will be the number of moles of O gas produced at 500 C temperature The reaction is carried in 2 litre vessel a 0 022 x 10 10 c 10 24 b 10 8 d 0 046 10 5

Arrange the following in order of decreasing number of unpaired electrons 1 Fe H 0 11 Fe CN III Fe CN 1 IV I II III 2 I II III IV 3 III II I IV The compound SiH N is expected to be IV Fe H O 4 II III I IV

3 Sandmeyer s reaction 4 Claisen condensation A greenish yellow gas reacts with an alkali metal hydroxide to form a halite which can be used in fireworks and safety matches The gas and halides respectively are 1 Br KBRO 2 Cl KCIO 3 1 Nalo 4 Cl NaCIO Sodium extract of an organic substance gives a blood red color with FeCl It contains the elements

In qualitative analysis the metals of Group I can be separated from other ions by precipitating them as chloride salts A solution initially contains Ag and Pb2 at a concentration of 0 10 M Aqueous HCI is added to this solution until the Cl concentration is 0 10 M What will the concentrations of Ag and Pb be at equilibrium Ksp for AgCl 1 8 x 10 10 Ksp for PbCl 1 7 x 10 5 1 Ag 1 8 x 10 11 M Pb 1 7 x 104 M 2 Ag 1 8 x 10 7 M Pb 1 7 x 10 6 M 3 Ag 1 8 x 10 11 M Pb2 8 5 x 10 5 M 4 Ag 1 8 x 10 9 M Pb 1 7 x 10 M

3 a b c and a p 7 90 a b c and a p 90 and y 120 When a 20 mL of 0 08 M weak base BOH is titrated with 0 08 HCL the pH of the solution at the end point is 5 What will be the pOH if 10 mL of 0 04 M NaOH is added to the resulting solution Giver log 2 0 30 and log 3 0 48 1 5 40 2 4 92 3 None of these 4 5 88

4 A solution of 500 ml of 0 2 M KOH and 500 ml of 0 2 M HCl is mixed and stirred the rise in temperature is T The experiment is repeated using 250 ml of each solution the temperature raised is T Which of the following is true a T T c T 4T b T 2T d T 9T

87 A new electron enters the orbital when 1 n m is maximum 2 n I is minimum 3 n I is maximum 4 n 1 is maximum 88 0 5 mol of Al2 SO4 3 contains 1 0 6 mol of oxygen atom 2 6 mol of oxygen atom 3 3 6 mol of oxygen atom 4 12 mol of oxygen atom

H C H Br A H CH3 Which of the following statement is true 1 A is formed by anti addition and is meso 2 A is formed by syn addition and is meso 3 A is formed by anti addition and is racemic 4 A is formed by syn addition and is racemic

3 CuS and ZnS 4 C If two molecules of A and B having mass 100 amu and 64 amu respectively and rate of diffusion of A 12x10 then what will be the rate of diffusion of B 1 15x10 2 64x10 3 5x10 and NIS 4 46x10

a 23 A saturated solution of Ca RCOO contains 0 6 mole in 2 litre solution pOH of the solution is 5 60 If 90 dissociation of the salt takes place then what is the pK of the carboxylic acid a 2 8 log 0 54 b 2 8 log 0 54 c 2 8 log 0 27 d None of these

When 100 mL of 1 0 M HCl is added to a 2 0 g piece of CaCO3 CO2 is produced at a certain rate Which of the changes below will NOT increase the rate of this reaction a b Adding 100 mL of 2 0 M HCl in place of 100 mL of 1 0 M HCl Heating the 100 mL of 1 0 M HCl before adding it to the CaCO3 c Adding 100 mL of 1 0 M HCl to 2 0 g of powdered CaCO3 d Adding 150 mL of 1 0 M HCl in place of 100 mL of 1 0 M HCI

1 2 40 of a mixture of 0 2 moles of N 0 6 moles of H react to give NH according to the equation N g 3H g 2NH g at constant T P Then ratio of final volume to initial volume of gases is a 4 5 c 7 10 b 5 4 d 8 5

In the following sequence of reactions the maximum number of atoms present in one plane o molecule C is Red hot A CH CI 1 eq Anhydrous AICI C Cu tube A is a lowest molecular weight alkyne B

27 According to the diagram given below the value of AH for conversion of A to B is a 40 c 120 Heat of Reaction 120 80 40 A B Reaction Course b 40 d 120 3

53 Two elements A and B combine to form two compounds A B and A2B5 If 0 2 mol of A B weighs 8 8 g and 0 1 mol of A2B5 weighs 10 8 g then atomic weight of A and B respectively are 1 16 u 12 u 2 12 u 16 u 3 14 u 16 u 4 16 u 14 u 54 If vapour density of a triatomic gas X3 is 150 then atomic mass of X is 1 60 u 3 100 u 2 90 u 4 120 u

a 35 The P T graph as given below was observed for process on an ideal gas Which of the following statement is true P A a W ve AH ve b W ve AH ve c W ve AH ve d W ve AH ve T B

9 For the reaction N 0 g 2NO g the equilibrium constant is K The equilibrium constant is K for the reaction 2NO g O g 2NO g What is K for the reaction NO g N g O g K K 1 4K K b 1 2K K K K

1 For a given mixture of NaHCO3 and Na2CO3 volume of a given HCl required is x ml with phenolphthalein indicator and further y ml required with methyl orange indicator Hence volume of HCl for complete reaction of original NaHCO3 is a 2x b c y X 2 d y x

pressure of H S g decreases at given temperature d All option are correct 19 200 mL of M 5 dibasic acid is mixed with 150 mL of M 2 monoacid base The pH of the resulting solution is likely to be a More than 7 c Equal to 7 b Less than 7 d Uncertain

Gold ornaments are made by alloying Au with Cu An ornament contains copper and gold in equimolar ratio in it Weight percentage of gold in the ornament is To the nearest integer Atomic mass of gold 197 and of copper 63 5 amu

18 Inert gas has been added to the following equilibrium system at constant volume SO g 1 2 0 g 0 g To which direction will the equilibrium shift a Forward b Backward c No effect d Unpredictable

2 Which of the following metal sulphide has maximum solubility in water a CdS K 36 10 sp b FeS K 11 10 2 sp c HgS K 32 10 54 sp d ZnS K 11 x 10 sp

Iron forms a sulphide with formula Fe7Sg Iron exist in both 2 and 3 oxidation states The ratio of Fe II atoms to Fe III atoms is Question Type Single Correct Type 1 2 3 3 4 4 3 2 5

A colloid prepared by the addition of KI to AgNO solution is purified using dialysis Find the minimum mass in grams of an electrolyte AB GMM 60 required to completely coagulate 1 of the aforementioned colloid Given Active ion causing flocculation A B Flocculation value mmol l 50 100

If pressure and temperature are kept constant the reaction of 18 mL of N gas with 54 mL of H gas will form Select one O a 27 Ob 9 c 108 O d 18 e 36 ml of ammonia

5 moles of nitrogen gas are enclosed in an adiabatic cylindrical vessel The piston itself is a rigid light cylindrical container containing 3 moles of Helium gas There is a heater which gives out a power 100 cal to the nitrogen gas A power of 30 cal is transferred to Helium through the bottom surface of the piston The rate of increment of temperature of the nitrogen gas assuming that the piston moves slowly He N 1 2K sec 2 4K sec 3 6K sec 4 8K sec

A freshly prepared Fe OH 3 precipitate is peptized by adding FeCl3 solution The charge on the colloidal particle is due to preferential adsorption of Question Type Single Correct Type 1 CI ions 2 Fe ions 3 OH ions

Two liquids A and B have vapour pressure in the ratio P Pg 1 3 at a certain temperature Assume A and B form an ideal solution and the ratio of mole fractions of A to B in the vapour phase is 4 3 Then the mole fraction of B in the solution at the same temperature is 1 2 3 4 1 5 5 1

d 8 5 33 A g B g AB g is a reversible reaction At equilibrium 0 4 mole of AB is formed when each A and B are taken one mole How much of A changes into AB a 20 c 60 b 40 d 4

c 10 3 d 10 2 45 The dissociation constant value of four acids are as follows Which of the values stand for strongest acid a 2x 10 4 b 2 x 10 c 3 10 4 d 0 02 10 46 Strongest lewis acid among the following in

Two mole of an ideal gas is expanded isothermally and reversibly from 1 litre ot 10 litre at 300 K The enthalpy change in kJ for the process is IIT JEE Screening 2004 1 11 4 kJ 2 11 4 kJ 3 0 kJ 4 4 8 kJ

44 4 4 g of an ideal gas mol wt 44 at 300K and 10 atm is allowed is allowed to expand isothermally against a external pressure of 1 atm Taking 1 L atm 100 J heat absorbed by the gas is a 200 5 J b 212 5 J c 221 4 J d 242 4 J

For which one of the following is AH re reaction equal to AH f for the product Question Type Single Correct Type 1 2 3 4 2CO g 02 g 2CO2 g N2 g 03 g N203 g CH4 g 2Cl2 g CH Cl2 e 2HCl g Xe g 2F2 g XeF4 s

7 If 0 3 mol of BaCl2 is mixed with 0 1 mol of Na2SO4 then the mass of precipitate formed is Atomic mass of Ba is 137 u 1 36 2 g 2 42 1 g 3 46 6 g 4 23 3 g 3 The weight of the residue obtained on strongly heating 21 g of MgCO3 is 1 10 g 3 7 g 2 12 g 4 15 g

Question 9 The digestive system is made up of the gastrointestinal tract also called the GI tract or digestive tract and the liver pancreas and gallbladder The GI tract is a series of hollow organs joined in a long twisting tube from the mouth to the anus The food and liquids pass through these organs during their processing and get converted into forms absorbable into the bloodstream i Digestion of food starts from which organ of the digestive system a Mouth due to the presence of saliva b Oesophagus that moves the food towards stomach c Small intestine that releases juices for fat breakdown d Stomach which helps in churning the food ii A student sets up an experiment to study the role of enzymes in digestion of food In which test tube the digestion of protein will occur a Test tube A as pepsin will breakdown into simple molecules b Test tube B as HCI will breakdown protein into simple molecules c Test tubes A as pepsin will breakdown protein into simple molecules d Test tube B as HCI will activate pepsin for breakdown of protein into simple molecules A Test tube Egg white Pepsin B Egg white Pepsin HCI iii Why is the inner wall of the alimentary canal not digested although the dige enzymes can digest all the materials that make cells 3 0

A sample of 5 litre gas in open vessel is taken at 300 K temperature and it is heated upto 450 K then what fraction of gas will escape out with respect to final volume 1 50 3 33 33 2 25 4 100

Consider the zinc blende structure formed by the sulphide ions occupying the FCC lattice points and zinc ions occupying some of the tetrahedral voids Select the correct statement about the crystal assuming it to be ideal The coordination number of Zn and S is same and equal to 4 The contribution of the S ions towards the packing efficiency is 74 approx The contribution of the Zn ions towards the packing efficiency is 1 approx The packing efficiency of the ZnS structure is 78 9 approx

c 44 g Match the mass of elements given in column I with the no of moles given in column II and mark the appropriate choice Column I Column II A 28 g of He 2 moles B 46 g of Na 7 moles C 60 g of Ca 1 mole D 27 g of Al 1 5 moles a A iv B iii C ii D i b A i B iii C ii D iv c A iii B ii C i D iv d A ii B i C iv D iii How many number of aluminium ions are present i ii iii iv

c A iii B ii C i D iv d A ii B i C iv D iii How many number of aluminium ions are present in 0 051 g of aluminium oxide a 6 023 x 100 ions c 6 023 x 10 ions b 3 ions d 9 ions

3 The anomeric carbon in D glucose is 1 C 1 carbon 2 C 2 carbon Correct sequence for reactivity of acid derivative is I RCO O II RCOCI 2 1 II II IV 1 II 1 II IV pH of a 10 10 M NaOH is nearest to 3 C 5 carbon III RCOOR 3 HI I IV III 4 C 6 carbon IV RCONH 4 I III II IV

the acid 18 A 45 C 40 B 53 D 63 18 If 1 2 g of a metal displaces 1 12 L of hydrogen at NTP equivalent mass of the metal would be A 1 2 x 11 2 C 24 B 12 D 1 2 11 2 19 The atomic weight of a metal M is 27 and its equivalent weight is 9 the formula of its chloride will be

T 7 moles of a tetra atomic non linear gas A at 10 atm and TK are mixed with 6 moles of another gas B at K and 5 atm in a closed rigid vessel witho 3 5T energy transfer with surroundings If final temperature of mixture was K then gas B is Assuming all modes of energy are active 6 monoatomic diatomic triatomic tetra atomic

74 75 In the given reaction what is B HS OH 1 H C S TsCl Pyridine OTS 2 A OH B OH 3 4 The unit cell cube length for LICI NaCl type structure is 5 14 A Assuming anion cation contact calculate the ionic radius for chloride ion