General Questions and Answers

Nuclear magnetic resonance is a on the interaction between the Select with a magnetic field The population difference in a typical magnetic field of several Tesla at room temperature is on the order of Select and the lower the temperature the Select fact if we can cool the sample from 300 K to 0 3 K the population difference will be on the order of Select spectroscopic technique relying Select Several factors determine the resonant frequency of NMR spectroscopy The major contribution is Select 1 order of Select the signal In which is caused by the frequency shift is Select field but the relative shift on the order of Select of the nucleus The absolute is typically used in NMR spectroscopy A minor factor influencing the actual resonant frequency is Select which is on the Hz the magnetic

6 Anthony wants to know which of five acids is the strongest He refers to a table of Acid Dissociation Constants K After consulting the table below which acid did he decide was the strongest A B Name Arsenic acid Carbonic acid Oxalic acid Phosphoric acid Sulfurous acid Arsenic acid Carbonic acid Formula H ANO H CO H C O H PO4 H SO C Oxalic acid D Sulfurous acid Ka 5 0 103 4 3 10 6 5 x 10 7 5 10 3 1 5 x 10 2

the for G A b d The population difference ina typical magnetic field of several tesla arder off at room is on the for 2 a b temperature the parts per thousand million trillion billion 2 Hited proportional not related to inversaly proportioneel temperature and the lower the signal Maltaust

3 The chair form of cyclohexane has protons in two distinct environments axial and equatorial When the proton NMR of cyclohexane is run on a 100 MHz instrument at 23 C only one signal for the com A See Answer Stack of the engi AC 150 1600D 40 Co o to c C A450 CION AC100 10 0 D NC 1 0 50 0 0 0 2 0 ap IMCO tr CGCT H T79 4CC0 00 Which of the following is an oxidation reduction reaction A Cu s 2AgNO aq 2Ag s Cu NO3 2 aq B HCl aq NaOH aq H 0 NaCl ag C

Nuclear magnetic resonance is a spectroscopic technique relying on the interaction between the Select with a magnetic field The population difference in a typical magnetic field of coural Tacle at raam temperature is on the agnetic resonance is a spectroscopic technique relying eraction between the Select gnetic field Th Select field of several Select electron spin ture the Selec nuclear magnetic dipole e can cool the s electronic magnetic dipole on difference will be on the order or

49 How many gram of ice at 0 C can be melted by the addition of 500 J of heat The molar heat of fusion for ice is 6 02kJmol 1 0 083 g 2 1 580 g 3 3 06 g 4 12 0 g 50 A 1 0 g sample of substance A at 100 C is added to 100 mL of H O at 25 C Using separate 100 mL portions of H O dura in ranaated with abetanco R and then with cubetanca C How will the final

0 In a solid AB having NaCl type structure A atoms occupy the corner of the cubic unit cell and the face centered positions If all the face centered atom along one of the axes are removed choose the correct options 3 Atomic weight of A 40 Atomic weight of B 60 r 1 4 r 2 8 A the packing fraction is 0 579 B The density of the resultant solid is 1 008 g cc C The packing faction is 0 679 D The density of the resultant solid is 2 008 g cc

Which is the most suitable reagent for the following transformation OH T CH CH CH CH CH CH CH CH CH CH CO H 1 alkaline kMnO 2 1 NaOH 3 Tollen s reagent 4 CrO CS

Alum is found to contain hydrated monovale cation M H O trivalent cation M H O Ja 3 SO2 in the ratio of 1 1 1 1 3 1 2 2 2 1 1 2 4 1 2 3

Question 5 00 mL of 0 10 M oxalic acid solution taken in a conical flask is titrated against NaOH from a burette using phenolphthalein indicator The volume of NaOH required for the appearance of permanent faint pink color is tabulated below for five experiments What is the concentration in molarity of the NaOH solution Exp No Vol of NaOH mL 1 2 3 4 5 12 5 10 5 9 0 9 0 9 0

1 poin A car rounds a horizontal curve of constant radius at a constant speed Which diagram best represents the directions of both the car s velocity v and acceleration a Option 1 Option 3 V a a Option 2 Option 4 a a

W W ext For a system undergoing a particular process the work done is dv 2 This equation is applicable to a a System that satisfies the van der Waals equation of state b Process that is reversible and isothermal c Process that is reversible and adiabatic d Process that is irreversible and at constant pressure

Problem 42 Assuming a nitrogen molecule spherical in shape and occupying the radius 200 pm calculate a the volume of single molecule of gas b the percentage of empty space in one mole of N gas at NTP

2 C H NH 3 C H OH 4 C H CI of urea are present in 100 mL of its solution The concentration of urea 1 C H NH 6 02 x 100 molecules solution is 1 0 02 M 2 0 001 M 3 0 01 M 4 0 1 M What mass of Agl will dissolve in 0 1 L of 1 0 M NH3 Neglect change in conc of NH3 Atomtextc weight of Ag I are 108 amu and 127 amu respectively

gy in the 2nd 2 3 4 eV 4 13 6 eV tic energy and the total aydrogen atom acco 44 Maximum frequency of emission is obtained for the transition 1 n 1 n 3 n 2 to n 1 2 to n 1 1 to n 2 2 n 6 to n 2 4 n 2 to n 6 per 45 If the ionization energy of hydrogen is 313 8 kcal 54

10 18 Conductivity of 0 01 M NaCl solution is M 0 00147 ohm cm What happens to this conductivity if extra 100 mL of H O will be added to the above solution a Increases b Decreases c Remains unchanged

7 How is the following transformation best carried out 1 OsO NaHSO 2 H SO H O 3 H SO H SO 4 HIO 3 Select the reagent used to bring about the following transformation But 2 ene to ethanol

Problem 34 Pay load is defined as the difference between the mass of displacce air and the mass of the balloon Calculate the pay load when a balloor of radius 10 m mass 100 kg is filled with helium at 1 66 bar at 27 C Density of air 1 2 kg mand R 0 083 bar dm K mol

2p 11 present in 139 Which of the following set of quantum numbers is correct for the 19th electron of Chromium S 1 2 1 2 1 2 10 n 1 3 2 3 3 4 l 0 2 0 m 0 2 0

3 A high pressure cell has a volume of 0 33 ft and contain gus cet 2500 psice and 130 F cet which conditions its 2 factor is 0 75 when 43 6 scf of the gas croe bled from the cell the pressure droped to 1 1000 Psia the tem pesuture 130 F what is the gas deviction factor cet Remaining at 1000 Psia and 130 F 2

Acid 1 has a pKa value of 6 Acid B has a pKa value of 2 Which statement below is accurate O Acid B is 100 000 000 times weaker than acid A O Acid B is 80 times stronger than acid A O Acid B is 100 000 000 times stronger than acid A O Acid B is 80 times weaker than acid A O Acid B is 8 times stronger than acid A Acid B is 8 times weaker than acid A

3 Nylons are usually hydrophobic The final product III obtained in the reaction H CH H 11 CH C C 0 CH CH C 0 1 CH 1 CH3 CH3 C CH CHCH CH OH CH OH CH3 H O NaBH CH3 C CH CH CH OH CH 3 CH 3 4 Nylons have very high mechanical strength II III is 2 CH3 CH3 C CH C CH OH CH CH 3 CH 3 CH3 C CH CH CH OH CH

What is the Bronsted Lowry definition of an acid Any substance that releases H ions when dissolved in water A proton acceptor A proton donor O Any substance that releases OH ions when dissolved in water O An electron donor An electron acceptor

Which of the following is an appropriate set of reactants for the preparation of 1 methoxy 4 nitrobenzene NO CH ONa 1 A NO CH Br 2 B 3 Both 1 and 2 4 none of these

25 mL of a solution of Na CO3 having a specific gravity of 1 25 g mL require 32 9 mL of a solution of HCI containing 109 5 g of the acid per litre for complete neutralization Calculate the volume of 0 84 N H SO4 that will be completely neutralized by 125 g of Na2CO3 solution A 420 mL B C skipped 520 mL 470 mL

Identify the correct statements regarding the structure of Al BH 1 Al is sp d and B is sp hybridized 2 It has 6 3c 2e bonds 3 It has 6 Al H Bbonds bonds 4 It has 6 2c 2e 1 Only 1 3 4 2 Only 1 2 3 3 Only 1 2 4 4 All of 1 2 3 and 4

4 SO SO SO HSO 3 H SO H SO SCL H The degree of hardness of water is usually expressed in terms of 1 g L of CaCO and MgCO present 2 ppm by weight of MgSO 3 ppm of CaCO actually present in water 4 ppm by weight of CaCO irrespective of whether it is actually present

What is the Arrhenius definition of an acid O An electron acceptor A proton donor O Any substance that releases OH ions when dissolved in water O A proton acceptor O An electron donor

The reduction of iron III oxide Fe O3 to pure iron during the first step of steelmaking 2 Fe O s 4 Fe s 30 g s driven by the high temperature combustion of coke a purified form of coal C s O g CO g uppose at the temperature of a blast furnace the Gibbs free energies of formation AG of CO and Fe O are 411 kl mol and 825 k espectively Calculate the maximum mass of pure iron that can be produced by the combustion of 8500 kg of coke ound your answer to 2 significant digits kg

Phosphoric acid H3PO4 is a triprotic acid with pKa values of 2 12 7 21 and 12 32 It is a useful buffer solution for pH values near the pKa values You have a 0 100 M solution of phosphate buffer with a pH of 2 50 How many mL of 0 500 M NaOH solution must be added to 1 00 L of this buffer solution to convert it to a buffer at pH 7 70

CHEMISTRY Microcosmic salt bead test of salt X yields semi translucent mass Therefore it contains 1 Co NO3 2 4 MnSO4 2 Ca NO3 2 3 CuSO4 CH H C Cl hv CH N isomeric products CH Cl M isomeric products

A ball of mass m is dropped onto a smooth fixed wedge of inclination 0 The collision is perfectly elastic If after the collision The x component of the velocity of the block is 2gh than 0 is Fixed 1 30 M m 0 2 45 3 60 4 15

If same type of atoms are packed in hexagonal close packing and cubic close packing separately then a density of hcp will be greater than ccp b density of hcp will be smaller than cep c density of hcp will be equal to ccp d density of hep and ecp will depend upon the temperature of the system COMEDK

Which statement is FALSE concerning the chemical reaction below Energy CaCO3 s CaO s CO2 g O A Rate k OB AG is temperature dependent OC The entropy of the products is greater than the entropy of the reactar OD The reaction is exothermic OE Increasing the temperature may increase the rate of this reaction

Substances are classified into different types on the basis of their magnetic properties Which of the following types have maximum magnetic moment aligned in a particular direction Diamagnetic Ferromagnetic

1 Explain why i A gas fill a vessel completely ii Camphor disappears without leaving any residue iii The temperature does not rise during the process of melting and boiling through heat energy is constantly supplied iv Water stored in an earthen vessel becomes cool v An iron almirah is a solid at room temperature

A mixture of 2 102 molecules of P and 3 10 molecules of Q weighs 0 60 g If the molecular mass of P is 45 then the molecular mass of Q will be N 6 10 A 45 C 90 B 180 D 270

Which statement concerning solution concentration is TRUE A A 5 0 ppm solution is more concentrated than a 5 0 m m solution OB A solution that is 1 5 ppt is less concentrated than a solution that is 1 5 ppm OC The ppm unit of concentration is typically used for very high concentrated solutions OD If a bottle is labeled 0 25 M Ca OH 2 the concentration of OH ions in solution is 0 50 M OE If a solution is 12 m m it will also be 12 m V

A solid XY has NaCl structure If radius of X is 100pm What is the radius of Y ion 1 120pm 2 136 6 to 241 6 pm 3 136 6pm Which type of chemical substance is Disparlure 4 241 6pm 1 Preservative 2 Pheromones 3 Antioxidant 4 Detergent At what temperature will the molar kinetic energy of 0 3 mol of He be the same as that of 0 4 mol of argon at 400K 1 700K 2 500K 3 800K 4 400K Reaction A B C D follows rate law R KIAF B12 starting with 1 M of A and B What is time

The minimum amount of O g consumed per gram of reactant is for the reaction Given atomic mass Fe 56 0 16 Mg 24 P 31 C 12 H 1 1 C3H g 5O g 3 CO g 4H O l 3 4 Fe s 3 O g 2 FeO3 s JEE MAINS C 2 P4 s 5O g P4010 s 4 2 Mg s O g 2 MgO s

What is the purpose of a control To determine the effect of a new variable on a system To influence a system in a predetermined way to test the hypothesis To alter a system in an unknown way to test the hypothesis To include a variable that could influence experimental results but does not reflect the planned changes that might re manipulating the independent variable

The effective nuclear charge often symbolized as Zeff or Z is the net positive charge experienced by an electron in a multi electron atom The term effective is used because the shielding effect of negatively charged electrons prevents higher orbital electrons from experiencing the full nuclear charge 15 18 you write shielding effect of negative charge electron and higher orbital electron now can we tell that shielding effect of negative charge electron is nucleus nearer electron and higher

When ferrous oxalate is titrated K Cr O milli equivalents of Fe C O2 and 4 2 Cr O in the redox reaction are X Y and Z 7 respectively then 1 X Y Y 2Y Z Y 2 X Y Z 4 2X 6Y 6Z

4 If both Assertion Reason are false Assertion On a rainy day it is difficult to drive car or bus at high speed Reason Assertion The value of coefficient of friction is lowered on wetting the surface It is difficult to move a cycle along the road with its brakes on

AAJ KA TOPPER In Dumas method 0 5 g of an organic compound containing nitrogen gave 112 ml of nitrogen at S T P The percentage of nitrogen in the given compound is 1 28 2 38 3 18 4 48 50 ml10N H SO 25 ml 12N HCL and 40ml SN HNO Were mixed together and the volume

wood charcoal The final concentration of the solution after adsorption is 0 5 M Amount of oxalic acid absorbed per gm of charcoal is A 3 45 gm B 3 15 gm

What is the molarity of a solution if 125 0 mL of it contains 6 89 g of KNO3 Molar mass KNO3 101 11 g mol A 0 545 M OB 0 554 M C 0 0545 M OD 5 45 x 104 M 5 54 x 104 M OES

The correct order of the decreasing ionic radii among the following isoelectronic species is 1 K Ca Cr S 2 Ca K S Cr 3 CI S Ca K 4 S C K Ca

The IUPAC name for Pt NH3 3 Br NO CI CI Question Type Single Correct Type 1 2 3 Triamminechloro bromo nitroplatinum IV chloride Triamminebromochloronitro platinum IV chloride Triammichlorobromoplatinum IV chloride Trimmingphloronitrobromo platinum IV

6 The chemical formula is a short form rep resentation of a a compound c a mixture b an element d an alloy 7 Na C O is the formula of sodium a carbonate b oxalate c formate d acetate