JEE MAIN - Chemistry (2003)

• 1

  Which one of the following statements is not true?

  คำตอบ

  (B)

  The pH of 1 $$\times$$ 10^-8 M HCl is 8
• 2

  The internal energy change when a system goes from state A to B is 40 kJ/mole. If the system goes from A to B by a reversible path and returns to state A by an irreversible path what would be the net change in internal energy?

  คำตอบ

  (C)

  Zero
• 3

  In an irreversible process taking place at constant T and P and in which only pressure-volume work is being done, the change in Gibbs free energy (dG) and change in entropy (dS), satisfy the criteria :

  คำตอบ

  (A)

  (dS)_{V, E} > 0, (dG)_{T, P} < 0
• 4

  The enthalpy change for a reaction does not depend upon :

  คำตอบ

  (B)

  the nature of intermediate reaction steps
• 5

  The correct relationship between free energy change in a reaction and the corresponding equilibrium constant K_c is :

  คำตอบ

  (C)

  - $$\Delta G^o$$ = RT ln K_c
• 6

  If at 298 K the bond energies of C - H, C - C, C = C and H - H bonds are respectively 414, 347, 615 and 435 kJ/mol, the value of enthalpy change for the reaction
  H₂C = CH₂(g) + H₂(g) $$\to$$ H₃C - CH₃(g) at 298 K will be :

  คำตอบ

  (C)

  - 125 kJ
• 7

  The solubility in water of a sparingly soluble salt AB₂ is 1.0 $$\times$$ 10^-5 mol L^-1. Its solubility product number will be :

  คำตอบ

  (D)

  4 $$\times$$ 10^-15
• 8

  Consider the reaction equilibrium
  2 SO₂ (g) + O₂ (g) $$\leftrightharpoons$$ 2 SO₃ (g); $$\Delta H^o$$ = -198 kJ
  One the basis of Le Chatelier's principle, the condition favourable for the forward reaction is :

  คำตอบ

  (B)

  lowering the temperature and increasing the pressure
• 9

  For the reaction equilibrium
  N₂O₄ (g) $$\leftrightharpoons$$ 2NO₂ (g)
  the concentrations of N₂O₄ and NO₂ at equilibrium are 4.8 $$\times$$ 10^-2 and 1.2 $$\times$$ 10^-2 mol L^-1 respectively. The value of K_c for the reaction is

  คำตอบ

  (B)

  3 $$\times$$ 10^-3 mol L^-1
• 10

  When rain is accompanied by a thunderstorm, the collected rain water will have a pH value :

  คำตอบ

  (D)

  slightly lower than that of rain water without thunderstorm
• 11

  The IUPAC name of CH₃COCH(CH₃)₂ is

  คำตอบ

  (C)

  3-methyl-2-butaone
• 12

  In the anion HCOO^$$-$$ the two carbon-oxygen bonds are found to be of equal length. What is the reason for it?

  คำตอบ

  (B)

  The anion HCOO- has two resonating structures
• 13

  The general formula C_nH_2nO₂ could be for open chain

  คำตอบ

  (A)

  carboxylic acids
• 14

  On mixing a certain alkane with chlorine and irradiating it with ultravioletlight, it forms only one monochloroalkane. This alkane could be

  คำตอบ

  (C)

  neopentane
• 15

  Butene-1 may be converted to butane by reaction with

  คำตอบ

  (C)

  Pd/H₂
• 16

  During dehydration of alcohols to alkenes by heating with conc. H₂SO₄ the initiation step is

  คำตอบ

  (D)

  protonation of alcohol molecule
• 17

  When CH₂ = CH - COOH is reduced with LiAlH₄, the compound obtained will be

  คำตอบ

  (A)

  CH₂ = CH - CH₂OH
• 18

  The correct order of increasing basic nature for the bases NH₃, CH₃NH₂ and (CH₃)₂ NH is

  คำตอบ

  (B)

  NH₃ < CH₃NH₂ < (CH₃)₂NH
• 19

  Ethyl isocyanide on hydrolysis in acidic medium generates

  คำตอบ

  (D)

  ethylamine salt and methanoic acid
• 20

  Complete hydrolysis of cellulose gives

  คำตอบ

  (B)

  D-glucose
• 21

  Which one of the following statements is correct?

  คำตอบ

  (A)

  From a mixed precipitate of AgCl and AgI, ammonia solution dissolves only AgCl
• 22

  Bottles containing C₆H₅l and C₆H₅CH₂I lost their original labels. They were labelled A and B for testing A and B were separately taken in test tubes and boiled with NaOH solution. The end solution in each tube was made acidic with dilute HNO₃ and then some AgNO₃ solution was added. Substance B gave a yellow precipitate. Which one of the following statements is true for this experiment?

  คำตอบ

  (D)

  A was C₆H₅I
• 23

  Among the following four structures $$i$$ to $$iv,$$
  
  
  
  it is true that

  คำตอบ

  (A)

  only $$i$$ and $$ii$$ are chiral compounds
• 24

  The reduction in atomic size with increase in atomic number is a characteristic of elements of

  คำตอบ

  (D)

  High atomic masses.
• 25

  The atomic numbers of Vanadium (V), Chromium (cr), Manganese (Mn) and Iron (Fe), respectively, $$23,24,25$$ and $$26$$. Which one of these may be expected to have the higher second ionization enthalpy?

  คำตอบ

  (A)

  Cr
• 26

  The reaction of chloroform with alcoholic $$KOH$$ and p-toluidine forms

  คำตอบ

  (C)

  
• 27

  The reason for double helical structure of $$DNA$$ is operation of

  คำตอบ

  (B)

  hydrogen bonding
• 28

  A red solid is insolvable in water. However it becomes soluble if some $$K{\rm I}$$ is added to water. Heating the red solid in a test tube results in liberation of some violet colored fumes and droplets of a metal appear on the cooler parts of the test tube. The red solid is :

  คำตอบ

  (A)

  $$Hg{{\rm I}_2}$$
• 29

  A pressure cooker reduces cooking time for food because

  คำตอบ

  (A)

  boiling point of water involved in cooking is increased
• 30

  In a 0.2 molal aqueous solution of a weak acid HX the degree of ionization is 0.3. Taking k_f for water as 1.85, the freezing point of the solution will be nearest to

  คำตอบ

  (D)

  -0.480^oC
• 31

  If liquids A and B form an ideal solution

  คำตอบ

  (D)

  the enthalpy of mixing is zero
• 32

  Standard reduction electrode potentials of three metals A,B&C are respectively +0.5 V, -3.0 V & -1.2 V. The reducing, powers of these metals are

  คำตอบ

  (D)

  B > C > A
• 33

  For a cell reaction involving a two-electron change, the standard e.m.f. of the cell is found to be 0.295 V at 25^oC. The equilibrium constant of the reaction at 25^oC will be

  คำตอบ

  (C)

  1 $$\times$$ 10¹⁰
• 34

  When during electrolysis of a solution of AgNO₃, 9650 coulombs of charge pass through the electroplating bath, the mass of silver deposited on the cathode will be :

  คำตอบ

  (A)

  10.8 g
• 35

  For the redox reaction Zn(s) + Cu²⁺(0.1 M) $$\to$$ Zn²⁺(1M) + Cu(s) taking place in a cell, $$E_{cell}^o$$ is 1.10 volt. E_cell for the cell will be ($$2.303{{RT} \over F}$$ = 0.0591)

  คำตอบ

  (B)

  1.07 volt
• 36

  Several blocks of magnesium are fixed to the bottom of a ship to :

  คำตอบ

  (B)

  prevent action of water and salt
• 37

  The radionucleide $${}_{90}^{234}Th$$ undergoes two successive $$\beta$$ -decays followed by one $$\alpha$$-decay. The atomic number and the mass number respectively of the resulting radionucleide are

  คำตอบ

  (B)

  90 and 230
• 38

  The half-life of a radioactive isotope is three hours. If the initial mass of the isotope were 256 g, the mass of it remaining undecayed after 18 hours would be

  คำตอบ

  (D)

  4.0 g
• 39

  In respect of the equation k = Ae^-E_a/RT in chemical kinetics, which one of the following statements is correct?

  คำตอบ

  (B)

  E_a is energy of activation
• 40

  The rate law for a reaction between the substances A and B is given by Rate = k[A]ⁿ [B]^m On doubling the concentration of A and halving the concentration of B, the ratio of the new rate to the earlier rate of the reaction will be as

  คำตอบ

  (C)

  2^{( n - m)}
• 41

  For the reaction system:
  
  2NO(g) + O₂(g) $$\to$$ 2NO₂(g) volume is suddenly reduce to half its value by increasing the pressure on it. If the reaction is of first order with respect to O₂ and second order with respect to NO, the rate of reaction will

  คำตอบ

  (B)

  increase to eight times of its initial value
• 42

  Which one of the following substances has the highest proton affinity?

  คำตอบ

  (B)

  NH₃
• 43

  For making good quality mirrors, plates of float glass are used. These are obtained by floating molten glass over a liquid metal which does not solidify before glass. The metal used can be :

  คำตอบ

  (D)

  mercury
• 44

  Glass is a :

  คำตอบ

  (A)

  super-cooled liquid
• 45

  What would happen when a solution of potassium chromate is treated with an excess of dilute nitric acid?

  คำตอบ

  (A)

  $$Cr_2O^{2-}_7$$ and H₂O are formed
• 46

  The atomic numbers of vanadium (V), Chromium (Cr), manganese (Mn) and iron (Fe) are respectively 23, 24, 25 and 26. Which one of these may be expected to have the highest second ionization enthalpy?

  คำตอบ

  (A)

  Cr
• 47

  Which one of the following nitrates will leave behind a metal on strong heating?

  คำตอบ

  (C)

  Silver nitrate
• 48

  Ammonia forms the complex ion [Cu(NH₃)₄]²⁺ with copper ions in alkaline solutions but not in acidic solutions. What is the reason for it?

  คำตอบ

  (A)

  In acidic solutions protons coordinate with ammonia molecules forming $$NH^+_4$$ ions and NH₃ molecules are not available
• 49

  The radius of La³⁺ (Atomic number of La = 57) is 1.06 Å. Which one of the following given values will be closest to the radius of Lu³⁺ (Atomic number of Lu = 71) ?

  คำตอบ

  (C)

  0.85 Å
• 50

  One mole of the complex compound Co(NH₃)₅Cl₃, gives 3 moles of ions on dissolution in water. One mole of the same complex reacts with two moles of AgNO₃ solution to yield two moles of AgCl (s). The structure of the complex is :

  คำตอบ

  (D)

  [Co(NH₃)₅Cl] Cl₂
• 51

  In the coordination compound, K₄[Ni(CN)₄], the oxidation state of nickel is :

  คำตอบ

  (A)

  0
• 52

  The pair of species having identical shapes for molecules of both species is

  คำตอบ

  (A)

  XeF₂, CO₂
• 53

  What volume of hydrogen gas at 273 K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by hydrogen?

  คำตอบ

  (A)

  67.2 L
• 54

  25 ml of a solution of barium hydroxide on titration with a 0.1 molar solution of hydrochloric acid gave a litre value of 35 ml. The molarity of barium hydroxide solution was

  คำตอบ

  (D)

  0.07
• 55

  The number of d-electrons retained in Fe²⁺ (At no of Fe = 26) ion is :

  คำตอบ

  (C)

  6
• 56

  The orbital angular momentum for an electron revolving in an orbit is given by $$\sqrt {l(l + 1)} {h \over {2\pi }}$$. This momentum for an s-electron will be given by

  คำตอบ

  (A)

  zero
• 57

  Which one of the following groupings represents a collection of isoelectronic species? (At. nos. : Cs : 55, Br : 35)

  คำตอบ

  (A)

  N^3-, F^-, Na⁺
• 58

  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 orbits in an atom of hydrogen

  คำตอบ

  (A)

  5 $$\to$$ 2
• 59

  The de Broglie wavelength of a tennis ball of mass 60 g moving with a velocity of 10 meters per second is approximately

  คำตอบ

  (D)

  10^-33 meters
• 60

  According to the Periodic Law of elements, the variation in properties of elements is related to their

  คำตอบ

  (B)

  atomic numbers
• 61

  Which one of the following is an amphoteric oxide?

  คำตอบ

  (D)

  ZnO
• 62

  An ethar is more volatile than an alcohol having the same molecular formula. This is due to

  คำตอบ

  (C)

  inter-molecular hydrogen bonding in alcohols
• 63

  Which one of the following pairs of molecules will have permanent dipole moments for both members

  คำตอบ

  (B)

  NO₂ and O₃
• 64

  Which one of the following compounds has the smallest bond angle in its molecule?

  คำตอบ

  (B)

  SH₂