Practice Questions

Q58.Given E∘ = −0.72 V, E∘ = −0.42 V. The potential for the cell Cr3+/Cr Fe2+//Fe Cr Cr3+(0.1M) Fe2+(0.01M) Fe is (1) 0.26 V (2) 0.399 V (3) −0.339 V (4) −0.26 V

Q59.For a reaction 1 A →2B, rate of disappearance of ' A ' is related to the rate of appearance of 'B' by the 2 expression (1) −d[A]dt = 12 d[B]dt (2) −d[A]dt = 14 d[B]dt (3) −d[A]dt = d[B]dt (4) −d[A]dt = 4 d[B]dt

Q60.Gold numbers of protective colloids A, B, C and D are 0.50, 0.01, 0.10 and 0.005, respectively. The correct order of their protective powers is (1) D < A < C < B (2) C < B < D < A (3) A < C < B < D (4) B < D < A < C

Q61.The hydrocarbon which can react with sodium in liquid ammonia is (1) CH3CH2CH2C ≡CCH2CH2CH3 (2) CH3CH2C ≡CH (3) CH3CH = CHCH3 (4) CH3CH2C ≡CCH2CH3

Q62.Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly? JEE Main 2008 JEE Main Previous Year Paper (1) Metal sulphides are thermodynamically more (2) CO2 is thermodynamically more stable than CS2 stable than CS2 (3) Metal sulphides are less stable than the (4) CO2 is more volatile than CS2 corresponding oxides

Q63.Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the main reason being (1) 4 f orbitals more diffused than the 5f orbitals (2) lesser energy difference between 5f and 6d than between 4f and 5d orbitals (3) more energy difference between 5f and 6d than (4) more reactive nature of the actinoids than the between 4f and 5d orbitals lanthanoids

Q64.Amount of oxalic acid present in a solution can be determined by its titration with KMnO4 solution in the presence of H2SO4 . The titration gives unsatisfactory result when carried out in the presence of HCl , because HCl (1) gets oxidised by oxalic acid to chlorine (2) furnishes H+ ions in addition to those from oxalic acid (3) reduces permanganate to Mn2+ (4) oxidises oxalic acid to carbon dioxide and water

Q65.The coordination number and the oxidation state of the element ' E ' in the complex [E(en)2 (C2O4)]NO2 (where (en) is ethylene diamine) are, respectively, (1) 6 and 2 (2) 4 and 2 (3) 4 and 3 (4) 6 and 3

Q66.In which of the following octahedral complexes of Co (at. no. 27), will the magnitude of Δ∘ be the highest? (1) [Co(CN)6]3− (2) [Co(C2O4)3]3− (3) [Co(H2O)6]3+ (4) [Co(NH3)6]3+

Q67.The organic chloro compound, which shows complete stereochemical inversion during a SN2 reaction, is (1) (C2H5)2CHCl (2) (CH3)3CCl (3) (CH3)2CHCl (4) CH3Cl

Q68.Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives (1) 2,4,6-trinitrobenzene (2) o-nitrophenol (3) p-nitrophenol (4) nitrobenzene

Q69.Bakelite is obtained from phenol by reacting with (1) (CH2OH)2 (2) CH3CHO (3) CH3COCH3 (4) HCHO Q70. α −D −(+)-glucose and β −D −(+) −glucose are (1) conformers (2) epimers (3) anomers (4) enantiomers JEE Main 2008 JEE Main Previous Year Paper

Q71.Statement - 1: For every natural number n ≥2, 1 + 1 + … + 1 > √n. Statement −2 : For every √1 √2 √n natural number n ≥2, √n(n + 1) < n + 1. (1) Statement −1 is false, Statement −2 is true (2) Statement −1 is true, Statement −2 is true, Statement −2 is a correct explanation for Statement −1 (3) Statement −1 is true, Statement −2 is true; (4) Statement −1 is true, Statement −2 is false. Statement −2 is not a correct explanation for Statement −1.

Q72.The quadratic equations x2 −6x + a = 0 and x2 −cx + 6 = 0 have one root in common. The other roots of the first and second equations are integers in the ratio 4 : 3. Then the common root is (1) 1 (2) 4 (3) 3 (4) 2

Q73.The conjugate of a complex number is 1 . Then the complex number is i−1 (1) −1 (2) 1 i−1 i+1 (3) −1 (4) 1 i+1 i−1

Q74.In a shop there are five types of ice-creams available. A child buys six ice-creams. Statement -1: The number of different ways the child can buy the six ice-creams is 10C5 . Statement −2 : The number of different ways the child can buy the six ice-creams is equal to the number of different ways of arranging 6 A's and 4 B's in a row. (1) Statement −1 is false, Statement −2 is true (2) Statement −1 is true, Statement −2 is true, Statement −2 is a correct explanation for Statement −1 (3) Statement −1 is true, Statement −2 is true; (4) Statement −1 is true, Statement −2 is false. Statement −2 is not a correct explanation for Statement −1.

Q75.How many different words can be formed by jumbling the letters in the word MISSISSIPPI in which no two S are adjacent? (1) 8 ⋅6C4 ⋅7C4 (2) 6.8 ⋅7C4 (3) 6 ⋅7 ⋅8C4 (4) 7 ⋅6C4 ⋅8C4

Q76.The first two terms of a geometric progression add up to 12. The sum of the third and the fourth terms is 48. If the terms of the geometric progression are alternately positive and negative, then the first term is (1) −4 (2) −12 (3) 12 (4) 4

Q77.Statement-1: ∑nr=0(r + 1)nCr = (n + 2)2n−1 Statement -2: ∑nr=0(r + 1)nCrxr = (1 + x)n + nx(1 + x)n−1 . JEE Main 2008 JEE Main Previous Year Paper (1) Statement −1 is false, Statement −2 is true (2) Statement −1 is true, Statement −2 is true, Statement −2 is a correct explanation for Statement −1 (3) Statement −1 is true, Statement −2 is true; (4) Statement −1 is true, Statement −2 is false. Statement −2 is not a correct explanation for Statement −1.

Q78.The perpendicular bisector of the line segment joining P(1, 4) and Q(k, 3) has y-intercept - 4. Then a possible value of k is (1) 1 (2) 2 (3) −2 (4) −4

Q79.The point diametrically opposite to the point P(1, 0) on the circle x2 + y2 + 2x + 4y −3 = 0 is (1) (3, −4) (2) (−3, 4) (3) (−3, −4) (4) (3, 4)

Q80.A parabola has the origin as its focus and the line x = 2 as the directrix. Then the vertex of the parabola is at (1) (0, 2) (2) (1, 0) (3) (0, 1) (4) (2, 0)

Q81.A focus of an ellipse is at the origin. The directrix is the line x = 4 and the eccentricity is 1/2. Then the length of the semi-major axis is (1) 8 (2) 2 3 3 (3) 4 (4) 5 3 3

Q82.Let p be the statement " x is an irrational number", q be the statement " y is a transcendental number", and r be the statement " x is a rational number iff y is a transcendental number". Statement −1 : r is equivalent to either q or p Statement −2 : r is equivalent to ∼(p ↔∼q). (1) Statement −1 is false, Statement −2 is true (2) Statement −1 is true, Statement −2 is true, Statement −2 is a correct explanation for Statement −1 (3) Statement −1 is true, Statement −2 is true; (4) Statement −1 is true, Statement −2 is false. Statement −2 is not a correct explanation for Statement −1.

Q83.The statement p →(q →p) is equivalent to (1) p →(p →q) (2) p →(p ∨q) (3) p →(p ∧q) (4) p →(p ↔q)