Practice Questions

Q29.The logic circuit shown below has the input waveforms 'A' and 'B' as shown. Pick out the correct output waveform. (1) (2) (3) (4)

Q31.In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005%. Certainity with which the position of the electron can be located is (h = 6.6 × 10−34 kg m2 s−1 , mass of electron, em = 9.1 × 10−31 kg ) (1) 1.52 × 10−4 m (2) 5.10 × 10−3 m (3) 1.92 × 10−3 m (4) 3.84 × 10−3 m

Q33.In which of the following arrangements, the sequence is not strictly according to the property written against it ? (1) CO2 < SiO2 < SnO2 < PbO2 : increasing (2) HF < HCl < HBr < HI : increasing acid oxidising power strength (3) NH3 < PH3 < AsH3 < SbH3 : increasing basic (4) B < C < O < N : increasing first ionization strength enthalpy.

Q35.Using MO theory predict which of the following species has the shortest bond length ? (1) O2+2 (2) O+2 (3) O−2 (4) O2−2 =

Q36.On the basis of the following thermochemical data: (ΔfG∘H+(aq) 0) H2O(ℓ) →H+(aq) + OH−(aq); ΔH = 57.32 kJ 1 H2( g) + O2( g) →H2O(ℓ); ΔH = −286.20 kJ 2 The value of enthalpy of formation of OH− ion at 25∘C is: (1) −22.88 kJ (2) −228.88 kJ (3) +228.88 kJ (4) −343.52 kJ

Q39.Arrange the carbanions, (CH3)3C, CCl3, (CH3)2CH, C6H5CH2 , in order of their decreasing stability : –––––––– (1) C8H5CH2 > CCl3 > (CH3)3C > (CH3)2CH (2) (CH3)2CH > CCl3 > C6H5CH2 > (CH3)3C –––––––– (3) CCl3 > C8H5CH2 > (CH3)2CH > (CH3)3C (4) (CH3)3C > (CH3)2CH > C6H5CH2 > CCl3

Q41.The number of stereoisomers possible for a compound of the molecular formula CH3 −CH = CH −CH(OH) −Me is : (1) 3 (2) 2 (3) 4 (4) 6

Q44.Two liquids X and Y form an ideal solution. At 300 K, vapour pressure of the solution containing 1 mol of X and 3 mol of Y is 550 mmHg. At the same temperature, if 1 mol of Y is further added to this solution, vapour pressure of the solution increases by 10 mmHg . Vapour pressure (in mmHg ) of X and Y in their pure states will be, respectively : (1) 200 and 300 (2) 300 and 400 (3) 400 and 600 (4) 500 and 600

Q45.A binary liquid solution is prepared by mixing n-heptane and ethanol. Which one of the following statements is correct regarding the behaviour of the solution? (1) The solution formed is an ideal solution (2) The solution is non-ideal, showing +ve deviation from Raoult's law. (3) The solution is non-ideal, showing -ve deviation (4) n-heptane shows +ve deviation while ethanol from Raoult's law. shows -ve deviation from Raoult's law.

Q46.In a fuel cell methanol is used as fuel and oxygen gas is used as an oxidizer. The reaction is CH3OH(ℓ) + 23 O2( g) →CO2( g) + 2H2O(ℓ) At 298 K standard Gibb's energies of formation for CH3OH(ℓ), H2O(ℓ) and CO2( g) are −166.2, −237.2 and −394.4 kJ mol−1 respectively. If standard enthalpy of combustion of methanol is −726 kJ mol−1 , efficiency of the fuel cell will be (1) 80% (2) 87% (3) 90% (4) 97%

Q47.Given : E∘ = −0.036 V, E∘ = −0.439 V. The value of standard electrode potential for the Fe3+/Fe Fe2+/Fe change, Fe3+(aq ) + e−→Fe2+(aq) will be : (1) −0.072 V (2) 0.385 V (3) 0.770 V (4) −0.270

Q48.The half life period of a first order chemical reaction is 6.93 minutes. The time required for the completion of 99% of the chemical reaction will be (log 2 = 0.301) : (1) 230.3 minutes (2) 23.03 minutes (3) 46.06 minutes (4) 460.6 minutes

Q51.Knowing that the Chemistry of lanthanoids (Ln) is dominated by its +3 oxidation state, which of the following statements in incorrect? (1) Because of the large size of the Ln (III) ions the (2) The ionic sizes of Ln (III) decrease in general bonding in its compounds is predominantly ionic with increasing atomic number. in character. (3) Ln (III) compounds are generally colourless. (4) Ln (III) hydroxides are mainly basic in character.

Q52.In context with the transition elements, which of the following statements is incorrect? (1) In addition to the normal oxidation states, the (2) In the highest oxidation states, the transition zero oxidation state is also shown by these metal show basic character and form cationic elements in complexes. complexes. (3) In the highest oxidation states of the first five (4) Once the d5 configuration is exceeded, the transition elements (Sc to Mn), all the 4s and 3d tendency to involve all the 3d electrons in electrons are used for bonding. bonding decreases.

Q53.Which of the following has an optical isomer ? (1) [CO(NH3)3Cl]+ (2) [CO( en )(NH3)2]2+ (3) [CO(H2O)4(en)]3+ (4) [CO(en)2(NH3)2]3+

Q54.Which of the following pairs represents linkage isomers ? (1) [Cu(NH3)4] [PtCl4] and [Pt(NH3)4] [CuCl4] (2) [Pd(PPh3)2(NCS)2] and [Pd(PPh3)2(SCN)2] (3) [CO(NH3)5NO3]SO4 and [CO(NH3)5SO4]NO3 (4) [PtCl2(NH3)4]Br and [PtBr2(NH3)4]Cl2

Q55.Which of the following on heating with aqueous KOH , produces acetaldehyde ? (1) CH3COCl (2) CH3CH2Cl (3) CH2ClCH2Cl (4) CH3CHCl2

Q57.In Cannizzaro reaction qiven below (1) the attack of : OH at the carboxyl group (2) the transfer of hydride to the carbonyl group (3) the abstraction of proton from the carboxylic (4) the deprotonation of PhCH2OH group JEE Main 2009 JEE Main Previous Year Paper

Q61.If the roots of the equation bx2 + cx + a = 0 be imaginary, then for all real values of x, the expression 3b2x2 + 6bcx + 2c2 is (1) greater than 4ab (2) less than 4ab (3) greater than −4ab (4) less than - 4ab

Q62.If z −4z = 2, then the maximum value of |z| is equal to (1) √3 + 1 (2) √5 + 1 (3) 2 (4) 2 + √2

Q63.From 6 different novels and 3 different dictionaries, 4 novels and 1 dictionary are to be selected and arranged in a row on the shelf so that the dictionary is always in the middle. Then the number of such arrangements is (1) less than 500 (2) at least 500 but less than 750 (3) at least 750 but less than 1000 (4) at least 1000

Q64.The sum to the infinity of the series 1 + 32 + 326 + 1033 + 1434 + … … is (1) 2 (2) 3 (3) 4 (4) 6

Q66.The lines p (p2 + 1)x −y + q = 0 and (p2 + 1)2x + (p2 + 1)y + 2q = 0 are perpendicular to a common line for (1) no value of p (2) exactly one value of p (3) exactly two values of p (4) more than two values of p

Q67.Three distinct points A, B and C are given in the 2 - dimensional coordinate plane such that the ratio of the distance of any one of them from the point (1, 0) to the distance from the point (−1, 0) is equal to 31 . Then the circumcentre of the triangle ABC is at the point JEE Main 2009 JEE Main Previous Year Paper (1) (0, 0) (2) ( 54 , 0) (3) ( 25 , 0) (4) ( 53 , 0)

Q69.The ellipse x2 + 4y2 = 4 is inscribed in a rectangle aligned with the coordinate axes, which in turn in inscribed in another ellipse that passes through the point (4, 0). Then the equation of the ellipse is (1) x2 + 16y2 = 16 (2) x2 + 12y2 = 16 (3) 4x2 + 48y2 = 48 (4) 4x2 + 64y2 = 48