General Questions and Answers

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

A diatomic molecule has a dipole moment of 1 2 D If its bond length is equal to 10 m then the fraction of an electronic charge on each atom will be 1 42 2 52 70 en farfars fa 1 2 D 1 42 10 m mm 2 52

xSn yCr O7 2 zH In acidic medium dichromate ion oxidizes stannous ion as zH aSn 4 bCr H O where x y z a b and c are respective stoichiometric coefficients Determine the value of x y z a b

46 What is the dominant intermolecular force or bond that must be overcome in converting liquid CH OH to a gas a Dipole dipole interaction b Covalent bonds c London dispersion force d Hydrogen bonding 2009

1 Arrange the following gases in the increasing order of b Give reason 02 CO H He ii Arrange the following gases in the decreasing order of magnitude of a Give reason CH4 0 H ns Molar volume occupied by the gas molecules size of the molecules and van der Waak constant b represents molar volume of the gas molecules Hence value of b increases in the following order TH H He O CO ii van der Waals constant a is the measure of magnitude of intermolecular attraction The magnitude of intermolecular attractions increases with increase in size of electron cloud in a molecule Hence for the given gases magnitude of a decreases in the following order CH4 O H Greater the size of electron cloud greater is the polarisability of the molecule and greater is the dispersion forces or London forces

M 2 0g of polybasic organic acid Molecular mass 600 required 100 mL of a NaOH solution for complete neutralisation Find the basicity of acid A mixture contains 1 0 mole each of NaOH Na CO and NaHCO When half of mixture is titrated with HCl it required a mole of HCI in presence of phenolphthalein In another experiment half of mixture required y mole of same HCI in presence of methyl orange Find the value of x y When Bro ion reacts with Br ion in acidic medium Br is liberated Calculate the ratio of molecular mass and equivalent mass of KBRO A volume of 12 5ml of 0 05 M SeO reacts with 28ml of 0 1M CISO which is oxidised to To what oxidation state was the selenium converted by the reaction A02558 impure sample of copper ore is dissolved and Cu is titrated with KT solution L

ir is trapped in a horizontal glass tube by 36 cm mercury column as shown below 1 atm Hg 136 cm the tube is held vertical keeping the open end up length of air column shrink to 19 cm What the length in cm by which the mercury column shifts down Elask containing air at 107 C and 722 mm of Hg is cooled to 100 K and 760 mm of Hg If msity in the initial condition 1 g cm then what is the final density g cm an ideal gas at 100 K is heated to 109 K in a rigid container the pressure increases by X at is the value of X e van der Waal s constants for a gas are a 3 6 atm L mol 2 b 0 6 L mol If R 0 08 L K mol and the Boyle s temperature K is Tg of this gas then what is the value of T 15 ask has 10 gas particles out of which four particles are moving at 7 ms aining are moving at the same speed of X ms If the r m s of the gas is 5 ms value of Y and the what is

what will be formula of compound 1 AB C D 3 AB C D 2 AB C D 4 None of these If the rate constant K of a reaction is 1 16 x 10 mol L min the order of reaction is 1 0 2 1 3 2 4 cannot be determined 1 AB C D 3 AB C D 67 af 2 AB C D 4 1 0 2 1 3 2 4 fuiff frai K 1 6 x 10 L z fe rit 1

Paragraph for Question Nos 26 and 27 10 5 g of a mixture containing P40 0 Na3PO4 and NaCl was dissolved in water and diluted to 250 cc In solution P 010 P4010 was hydrolysed completely to phosphoric acid H PO4 The resulting solution was analy volumetrically Atomic masses of P 31 Na 23 O 16 26 If 35 ml of above stock solution was titrated using 1 1 N NaOH solution 15 ml of base was requied to reach equivalance point Molarity of H PO4 in solution was approximately A 0 7 C 0 9 B 0 8 D 0 16

If the average molecular mass of air is 29 then assuming N and O gases are there which options are correct regarding composition of air i 75 by mass of N2 ii 75 by moles N2 iii 72 41 by mass of N A Only i is correct B only ii is correct C Both ii and iii are correct D both i and ii are correct

1 Correct IUPAC name of the following compound is 1 4 1 1 dimethylethyl 5 ethyloctane 2 5 ethyl 4 1 1 dimethylethyl octane 3 5 1 1 dimethylethyl 4 ethyloctane

Q 27 The magnitude of surface tension of liquid depends on the attractive forces between the molecules Arrange the following in increasing order of surface tension Dy Water alcohol C H5OH and hexane CH3 CH 4 CH3

Identify the wrong statement from following about Ellingham diagram 2 It tells about the stability of oxide 1 It gives rate of reaction Re 3 It gives idea about reduction of metal oxide 4 It gives idea about free energy of reduction 6 1 Ellingham diagram do not gives any idea about rate of reaction rest all statement are correct renc

4 n 3 1 m 1 s 2 How much volume of 5M HNO is required to oxidise 16 g Fe if HNO is converting into NO 1 16 ml 2 19 05 ml 4 32 ml 3 38 1 ml The compound X C H reacts with ammonical AgNO to give a white precipitate and reacts with 52 53 4 n 3 f 1 m 1 s 16 Fe ffe SM HN A SIRA Safe HNO NO uftenta ar 12 1 16 ml 3 38 1 ml 2 19 05 ml 4 32 ml X C H if AgNO fa K

Calculate your specific activity based on 3H 5 x 10 15 abundance 14C 1 2 x 10 10 abundance and 40K 1 17 x 10 3 abundance Assume you are 23 2 carbon 11 6 hydrogen and 0 35 potassium by weight 2 points

1 mole of ferric oxalate Fe2 C2O4 3 is oxidised by x mole of MnO4 in strong basic medium and 1 mole of ferrous oxalate FeC204 is oxidised by y mole of MnO4 in acidic medium Ratio of x y is 02 1 0 10 1 03 1 01 3

of angular hodes and number of radial nodes in the orbital to which last electron of chromium present What is the total number of radial and angular nodes present in 5f orbital Infrared lamps are used in restaurants to keep the food warm The infrared radiation is strongly absorbed by water raising its temperature and that of the food If the wavelength of infrared radiation is assumed to be 1500 nm and the number of quanta of infrared radiation produced per second by an infrared lamp that consumes energy at the rate of 100 W and is 12 efficient only is xx 10 then the value of x is xis gy vsJ Given h 6 625 x 107 J s When an electron makes transition from n 1 state to n state the wavelength of emitted adiations is related to n n 1 according to x n What is the value of x

halpy of neutralisation of HCl by NaOH is 57 kJ mol and with NH4OH is 50 kJ mol late enthalpy of ionisation of NH4OH aq e energy of NaCl s is 790 kJ mol and enthalpy of hydration is 785 kJ mol ate enthalpy of solution of NaCl s mple of NH4NO3 is decomposed in a Bomb calorimeter The temperature of calorime se by 4 C The heat capacity of the system is 1 25 kJ C Calculate the value of x molar heat of decomposition of NH4NO3 at constant volume is 400 kJ mol engine operating between 227 C and 77 C absorbs 10 kcal of heat from the 227 bir reversibly per cycle Calculate total work done in kcal in two cycles ate work done in chemical reaction in kcal 3B g C l at 227 C at 1 atm in closed vessel ole ideal monoatomic gas is heated according to path AR and

In question if it ato is asked the product for the reaction HCCH Na K Then what to will be the answer Monosodium ethynide or Disodium ethynide CH CNa or Nae C Na La HERE How the Question can be given tricky in Neet to confuse the student Please help me clarify this cpt problem T

eal gas is expanded according to PV constant under very ligi tion mode active Calculate the molar heat capacity of gas in cal molK in is operating between 500 K to 300 K and it absorbs 10 kcal of heat from 500K sibly per cycle Calculate the work done in kcal per cycle le involving ideal non linear triatomic gas if during adiabatic expansion volume 2L to 16L and heat absorbed during isothermal expansion is 8 kcal then itude of work done by carnot engine in kcal olioxs 29mmob

22 Mr Santa has to decode a number ABCDEF where each alphabet is represented by a single digit Suppose an orbital whose radial wave function is represented as below and angular function is 1 2 r k r k ekz r 5k r 6k3 From the following information given about each alphabet then write down the value of A B C D E F where each alphabet corresponds to a value Info A Value of n where n is principal quantum number Info B Number of angular nodes Info C Azimuthal quantum number of subshell to which orbital belongs Info D Number of subshells having energy between n 5 s to n 5 p where n is principal quantum number Info E Orbital angular momentum of given orbital Info F Radial distance of the spherical node which is farthest from the nucleus Assuming k 1

is negligible The graph of compressibility factor Z vs P for one mole of a real gas is shown in follow diagram The graph is plotted at constant temperature 273 K If the slope of graph at very atm then calculate volume of one mole of real gas molecules dz pressure dp 2 8 in L mol Given N 6x 1023 and R 3 Steth 22 4 273 Z L atm K mol 1 ITVAMITATE 28 atm 100 I TRAMATAN dP 13 2 TRIMITATE S THAMATAN Under the identical conditions of temperature the density of a gas X is two times to that of p Y while molecular mass of gas Y is three times that of Y Calaul

27 HCl was passed through a solution of CaCl2 MgCI and NaCl Which of the following compound s crystallise s Both MgCl and CaCl Only NaCl Only MgCl NaCl MgCl and CaCl 28 Anisole on cleavage with HI gives 1 2 3 4 OH

121 In set of reaction ethyl benzene yielded a product D CH CH D would be 1 2 3 COOCH Br Br KMnO B KOH CH CH COOCH Br Br CH COOCH COOH Brz C C H OH D Feds

7 Calculate the number of waves made by a Bohr electron in one complete revolution in nth orbit of He ion if ratio of de Broglie wavelength associated with electron moving in n and 2 brbit is 2 0

104 A two dimensional solid is made by alternating circles with radius a and b such that the sides of the circles touch The packing fraction is defined as the ratio of the area under the circles to the area under the rectangle with sides of length x and y X y 2a bi x 2a 2b The ratio r b a for which the packing fraction is minimized is closest to A 0 41 B 1 0 C 0 50 D 0 32

500 ml of each three sample of H O2 labelled 10 V 15V and 20 V are mixed and then diluted with equal volume of water The volume strength of resultant H O2 solution is Considering 1 mole of gas at STP 22 7 L

0 1 mole H3POx is completely neutralised by 5 6 g KOH then the true statement is O x 3 and given acid is dibasic O x 4 and given acid has no P H linkage O x 2 and given acid has two P H linkage All of these

Avogadro number is 1 Number of atoms in one gram of the element 2 Number of mililitre which one mole of a gaseous substance occupies at NTP 1 atm 0 3 Number of molecules present in one gram molecular mass of a substance 4 All are correct

A tetravalent element forms monoxide and dioxide with oxygen When air is passed over heated element 1273 K producer gas is obtained Monoxide of the element is a powerful reducing agent and reduces ferric oxide to iron Identify the element and write formulas of its monoxide and dioxide Write chemical equations for the formation of producer gas and reduction of ferric oxide with the monoxide

Semiconduction non stoichiometric nickel II oxide can be prepared by the reaction of stoichiometric compound with oxygen gas What volume of oxygen gas at 25 C and 2 5 atm would be consumed in converting 1 0 kg of NiO to the appropriate amount of Ni0 9701 00 What mass of semiconductor would be produced

inflated to a immersed to the bottom of a lake its volume reduce to 1 25 L Assuming atmospheric pressure to be equivalent to 10 m column of water and no change in temperature if the depth of the lake is x x 10 cm what is the value of x A gaseous mixture containing equal moles of H 0 and He is subjected to series of effusion steps The composition by moles of effused mixture after 4 effusion steps is x 1 y X respectively Then find the value of One mole of a gas changed from its initial state 15L 2 atm to final state 4L 10 atm eversibly If this change can be represented by a straight line in P V curve maximum emperature approximate the gas attained is xx 102K Then find the value of x Two moles of an ideal gas undergoes the following process Given that OP is x x 10 then Tv

Question 2 A 5 0 cm solution of H O liberates 0 508 g of I from an acidified KI solution The strength of H O solution in terms of volume strength at STP is Options a 2 24 vol b 8 96 vol c 1 12 vol d 4 48 vol

5 A co ordination complex of cobalt has molecular formula 65 containing five ammonia molecules one nitro group and two chlorine atoms for one cobalt atom One mole of this compound produces three mole ions in an aqueous solution In reacting this solution with excess of silver nitrate solution two moles of AgCl get precipitated The ionic formula of this complex would be 1 Co NH3 4 NO C NH3 C 2 CO NH3 CI CI NO 3 CO NH3 NO Cl 4 ICO NH 1 NO C Te face n en casa fac fuffrage fant AgCl se 1 Co NH3 NO C NH 2 CO NH3 a C NO 3 CO NH3 NO 4 CO NH3 NO

Industrial process a Haber s process b Ostwald s process Application i HNO3 synthesis ii Aluminium extraction c Contact process iii NH3 synthesis d Hall Heroult process iv H SO4 synthesis Choose the correct answer from the options given below 1 a ii b iii c iv d i 2 a iii b iv c i d ii 3 a iii b i c iv d ii

79 Q 18 A salt X is heated to become its dehydrated form Y and this Y after mixing with water becomes X that can be used for white washing of walls and this solution dries very quickly and become hard mass Y The substance X and Y respectively is Full Marks 1 a Calcium oxide and calcium hydroxide b Calcium carbonate and calcium oxide c POP and gypsum d Gypsum and POP

NH 5 6 NaNO HCI X 273 278 K 1 X 2 X In the above chemical reaction intermediate X and reagent condition A are 3 X 4 X N CI NO A NO N CI Major Product A H O NaOH A H O A OH A H O A A H O NaOH

81 Q 20 The oxidation different from combustion of ethanol because Full Marks a Oxidation requires 1 O atom but combustion requires 1 molecule of O b Oxidation gives acid but alcohol give CO2 and H2O c Heat is liberated in combustion but heat is supplied in oxidation d All of the above

Given below are two statement one is labelled as Assertion A and the other is labelled as Reason R Assertion A Size of Bk ion is less than Np ion Reason R The above is a consequence of the lanthanoid contraction In the light of the above statements choose the correct answer from the options given below 1 A is false but R is true 2 Both A and R are true but R is not the correct explanation of A 3 Both A and R are true and R is the correct explanation of A 4 A is true but R is false

Q7 A homogeneous gas reaction A 3R has a reported rate at 215 C A 10 2C5 mol liter sec Find the space time needed for 80 conversion of a 50 A 50 inert feed to a plug flow reactor operating at 215 C and 5 atm CAO 0 0625 mol liter 24

Which among the following pairs of Vitamins is stored in our body relatively for longer duration 1 Thiamine and Vitamin A 2 Vitamin A and Vitamin D 3 Thiamine and Ascorbic acid 4 Ascorbic acid and Vitamin D

3 Ans E ans Why do hydrocarbon molecules with an odd number of carbons atoms have lower melting points than those with an even number of carbon atoms Identify the structure of A and B CH3 CH COOH Wbu de KOH A Kolbe s electrolysis B bonds rather than C H bonds break during cracking of alkanes

B CH CH CH II CH CH CH 1 III Which of following orders is correct for heat of hydrogenatio of these compounds 1 I II III 2 III II I 3 II III I

Quinhydrone is a sparingly soluble one to one addition compound formed from hydroquinone and quinone When solid quinhydrone is dissolved in an aqueous medium equal concentrations of hydroquinone and quinone result If a platinum wire is dipped into the solution the potential of the electrode is governed by the reversible reaction 2H 2e OH OH H Q Where Q denotes quinone and H Q denotes hydroquinone The E value of this half cell reaction is 0 46V with respect to the saturated calomel reference electrode SCE Because the potential of the quinine hydroquinone half reaction depends on the concentration of hydrogen ion it is possible to use this system to measure pH A sample solution of unknown pH was saturated with quinohydrone and a platinum electrode was dipped into it If the potential of the such electrode was found to be 0 22V with respect to SCE what was the PH of the sample solution 2 303 RT Given 0 06 F

Calculate the wavelength in nanometer associated with a 73 proton moving at 1 0x10 ms Mass of proton 1 67x10 27 1 0 40 nm 2 2 5 nm 3 14 0 nm kg and h 6 63 x 10 Js C

Which statement is true for solution of 0 020 M H SO4 2 a 2 litre of the solution contains 0 020 mole of SO b 2 litre of the solution contains 0 080 mole of H30 c 1 litre of the solution contains 0 020 mole H30 d None of these

Metal M is the most abundant metal in the Earth crust Its electronic configurat ion is 2 8 3 and occurs in the Earth cru st as its oxides M203 Name the ore of t he metel containing M203 Explain the method used for concentration of the o re Also give reason for choosing that method

Q 55 If the value of Ksp for Hg Cl s is X then the value of X will be where pX log X Given Hg Cl s 2e 2Hg 1 2Cl 2 Hg 2e 2Hg 1 E 0 27 V E 0 81 V

4 6 02 10 4 6 02 x 10 63 An alkyl bromide X reacts with Na to form 4 5 63 X fear fa diethyloctane Compound X is Ext 1 CH CH Br 2 CH CH Br 3 CH CHL CH Br CH 1 CH CH Br 2 CH CH Br 3 CH CH CH Br CH 4 CH CH CH Br CH CH 64 Which will dehydrate easily 4 CH CH CH Br CH CH 64 faran facicera sar

13 Following is the composition of a washing soda sample Substance Molecular Wt Mass percent Na CO3 NaHCO3 NaCl 106 0 84 0 58 5 a 9 mol of CO c 17 mol of CO On complete reaction with excess HC1 one kilogram of the washing soda will evolve 84 8 8 4 6 8 b 16 mol of CO d 18 mol of CO