Solution - Career Point

28. Assertion : A rocket moves forward by pushing thesurrounding air backwards.Reason : It derives the necessary thrust to moveforward, according to Newton's third law of motion.(A) Both Assertion and Reason are true and Reasonis a correct explanation of the Assertion(B) Both Assertion and Reason are true but Reason isnot a correct explanation of the Assertion(C) Both Assertion and Reason are false(D) Assertion is false but the Reason is true29. While slipping on rough spherical surface of radius'R', block A of mass 'm' comes with velocity 1 .4gRat bottom B. Work done in slipping the block from'B' to 'C' is –(A)mgR4(C) 1.3 mgRmAB(B) mgRC(D) 45 mgR30. A 2000 kg rocket in free space expels 0.5 kg of gasper second at exhaust velocity 400 ms –1 for 5seconds. What is the increase in speed of rocket inthis time -(A) 2000 ms –1 (B) 200 ms –1(C) 0.5 ms –1 (D) zeroCHEMISTRY31. Which of the following can act as a both Bronstedacid & Bronsted base -(A) Na 2 CO 3 (B) OH ––(C) HCO 3 (D) NH 332. In which compound the oxidation No. of Oxygenis + 21 -(A) OF 2 (B)O 2 F 2(C) O 2 [PtF 6 ] (D) KO 233. The favourable conditions for a spontaneousreactions are -(A) T ∆S > ∆H, ∆H = ⊕ , ∆S = ⊕(B) T ∆S > ∆H, ∆H = ⊕ , ∆S = Θ(C) T ∆S = ∆H, ∆H = Θ , ∆S = Θ(D) T ∆S = ∆H, ∆H = ⊕ , ∆S = ⊕34. The substance not likely to contains CaCO 3 is -(A) Dolomite (B) A marble statue(C) Calcined Gypsum (D) Sea shells35. On mixing 10ml of acetone with 50ml of CHCl 3 , thetotal volume of the solutions-(A) < 60ml(B) > 60ml(C) = 60ml(D) unpredictable36. On addition of He gas at constant volume to thereaction N 2 + 3H 2 2NH 3 at equilibrium-(A) The reaction stops(B) Forward reactions is favoured(C) Reaction remains unaffected(D) Backward reactions is favoured37. The half life of a reaction is 24 hours . If we startwith 10gm of reactant, How many grams of it willreaction after 96 hours, (I order reaction)(A) 0.625gm (B) 6.25gm(C) 1.25gm (D) 0.125gm38. The current is passed in Ag 2 SO 4 aqueous solution &1.6 gm O 2 is obtained. The amount of Ag depositedwill be- [Ag = 108gm](A) 107.8g (B) 1.6g (C) 0.8g (D) 21.6g39. In decinormal solution CH 3 COOH is ionized to theextent of 1.3% find the pH of solution.(A) 3.89 (B) 2.89 (C) 4.89 (D) 5.8940. A FCC element (atomic wt.= 60) has a cell edge of400pm. Its density is-(A) 6.23 g/cm 3 (B) 6.43 g/cm 3(C) 6.53 g/cm 3 (D) 6.63 g/cm 341. Which set of quantum No. is not possiblenl m s(A) 2 0 0 +1/2(B) 4 2 –3 –1/2(C) 3 2 –2 +1/2(D) 2 1 0 +1/242. Give simplest formula of compound whichcontaining 6gm C, 3.01×10 23 atom O and 2 mole Hatoms-(A) CH 2 O (B) CH 4 O (C) CHO (D) CH 3 O43. The IUPAC Name of(A) 1,2-dimethyl Cyclohexene(B) 2,3-dimethyl Cyclohexene(C) 1,2-dimethyl Cyclohex-2-ene(D) 5,6-dimethyl Cyclohex-1-ene44. Which of the following reagent can make distinctionbetween Pri. and Sec. amines ?(A) NH 3(B) NaNO 2 /HCl(C) HCl(D) AllXtraEdge for IIT-JEE 72APRIL 2010