JEE MAIN - Chemistry (2011)

• 1

  Ethylene glycol is used as an antifreeze in a cold climate. Mass of ethylene glycol which should be added to 4 kg of water to prevent it from freezing at −6^oC will be : [K_f for water = 1.86 K kg mol⁻¹ , and molar mass of ethylene glycol = 62 g mol⁻¹ )

  回答

  (D)

  804.32 g
• 2

  A 5.2 molal aqueous solution of methyl alcohol, CH₃OH, is supplied. What is the mole fraction of methyl alcohol in the solution ?

  回答

  (B)

  0.086
• 3

  Ozonolysis of an organic compound gives formaldehyde as one of the products. This confirms the presence of :

  回答

  (A)

  a vinyl group
• 4

  Identify the compound that exhibits tautomerism.

  回答

  (B)

  2-Pentanone
• 5

  A vessel at 1000 K contains CO₂ with a pressure of 0.5 atm. Some of the CO₂ is converted into CO on the addition of graphite. If the total pressure at equilibrium is 0.8 atm, the value of K is :

  回答

  (D)

  1.8 atm
• 6

  The entropy change involved in the isothermal reversible expansion of 2 moles of an ideal gas from a volume of 10 dm³ to a volume of 100 dm³ at 27^oC is :

  回答

  (D)

  38.3 J mol^-1 K⁻¹
• 7

  The degree of dissociation ($$\alpha$$ ) of a weak electrolyte, A_xB_y is related to van’t Hoff factor (i) by the expression :

  回答

  (D)

  $$\alpha = {{i - 1} \over {(x + y - 1)}}$$
• 8

  Trichloroacetaldehyde was subjected to Cannizzaro’s reaction by using NaOH. The mixture of the products contains sodium trichloroacetate and another compound. The other compound is :

  回答

  (D)

  2, 2, 2-Trichloroethanol
• 9

  The outer electron configuration of $$Gd$$ (Atomic No. $$64$$) is :

  回答

  (D)

  $$4{f^7}\,5{d^1}\,6{s^2}$$
• 10

  Outer electronic configuration of Gd (Atomic no : 64) is -

  回答

  (C)

  4f⁷5d¹6s²
• 11

  The presence or absence of hydroxyl group on which carbon atom of sugar differentiates RNA and DNA ?

  回答

  (A)

  2^nd
• 12

  Silver Mirror test is given by which one of the following compounds ?

  回答

  D

  B
• 13

  Sodium ethoxide has reacted with ethanoyl chloride. The compound that is produced in the above reaction is

  回答

  (C)

  Ethyl ethanoate
• 14

  The strongest acid amongst the following compounds is :

  回答

  (B)

  CH₃CH₂CH(Cl)CO₂H
• 15

  Which of the following reagents may be used to distinguish between phenol and benzoic acid ?

  回答

  (C)

  Neutral FeCl₃
• 16

  Phenol is heated with a solution of mixture of KBr and KBrO₃. The major product obtained in the above reaction is

  回答

  (C)

  2, 4, 6- Tribromophenol
• 17

  The magnetic moment (spin only) of [NiCl₄]²⁻ is

  回答

  (B)

  2.82 BM
• 18

  Which of the following facts about the complex [Cr (NH₃)₆ ]Cl₃ is wrong?

  回答

  (B)

  The complex is an outer orbital complex
• 19

  In context of the lanthanoids, which of the following statements is not correct?

  回答

  (C)

  Availability of 4f electrons results in the formation of compounds in +4 state for all the members of the series.
• 20

  Which of the following statements regarding sulphur is incorrect?

  回答

  (C)

  The oxidation state of sulphur is never less than +4 in its compounds
• 21

  Which of the following statement is wrong?

  回答

  (D)

  The stability of hydrides increases from NH₃ to BiH₃ in group 15 of the periodic table
• 22

  The rate of a chemical reaction doubles for every 10^oC rise of temperature. If the temperature is raised by 50^oC , the rate of the reaction increases by about :

  回答

  (B)

  32 times
• 23

  The reduction potential of hydrogen half cell will be negative if :

  回答

  (C)

  p(H₂) = 2 atm and [H⁺] =1.0 M
• 24

  The structure of IF₇ is :

  回答

  (C)

  pentagonal bipyramid
• 25

  The hybridization of orbitals of N atom in $$NO_3^-$$, $$NO_2^+$$ and $$NH_4^+$$ are respectively :

  回答

  (B)

  sp², sp , sp³
• 26

  Among the following the maximum covalent character is shown by the compound :

  回答

  (B)

  AlCl₃
• 27

  Which one of the following order represents the correct sequence of the increasing basic nature of the given oxides ?

  回答

  (B)

  Al₂O₃ < MgO < Na₂O < K₂O
• 28

  A gas absorbs a photon of 355 nm and emits at two wavelengths. If one of the emissions is at 680 nm, the other is at :

  回答

  (B)

  743 nm