Tiêu đề 04. CHEMICAL KINETICS.pdf ✅

PAPER 1 (1.) (g g g ) ( ) ( ) A + → 3 B 2C , The rate of this reaction d A  dt   −     is 3 1 1 3 10 mollit min − − −  what is the value of d B  dt   −     in mol liter −1 min −1 : (1) 3 3 10−  (2) 3 10− (3) 3 9 10−  (4) 3 1.5 10−  (2.) For the reaction 2 5 2 2 2 N O 4NO O → + rate of reaction will be : (1)  2 5  1 N O 2 d dt       (2)  2 5  d 2 N O dt       (3)  2  1 d NO 4 dt       (4)  2  d 4 NO dt       (3.) For a gaseous reaction following data is given : 15 2000/ 1 14 1000/ 2 10 10 T T A B K e C DK e − − → = → = The temperature at which K K 1 2 = is : (1) 1000 K (2) 2000 K (3) 868.82 K (4) 434.2 K (4.) Inversion of cane sugar in dilute acid is : (1) Bimolecular reaction (2) Pseudo uni molecular reaction (3) unimolecular reaction (4) trimolecular reaction (5.) The rate of gaseous reaction is given by the expression 2 3 K A] B]     . The volume of reaction vessel is suddenly reduced to one half of the initial volume. The reaction rate relative to the original rate will be : (1) 1/ 24 (2) 1/ 32 (3) 32 (4) 24 (6.) The rate constant of reaction : 2H O aq 2H O I O g 2 2 2 2 ( ) → + ( ) ( ) is 3 1 3 10 min − −  at what concentration of H O2 2 , the rate of the reaction will be 4 1 2 10 ms − −  : (1) 3 6.67 10 M−  (2) 2M (3) 4M (4) 0.08M (7.) Rate constant k of a first order reaction is related to initial concentration C0 and Ct at time t by the equation ln ln o t kt C C = − . The graph is straight line if we plot : (1) t vs 0 lnC (2) t vs lnCt (3) 1 t − vs lnCt (4) lnCo vs lnCt (8.) Half-life of a substance A following first order kinetics is 5 days. Starting with 100 g of A , amount left after 15 days is :
(1) 25 g (2) 50 g (3) 12.5 g (4) 6.25 g (9.) In a first order reaction, the conc. of reactant decreases from 0.8M to 0.4M in 15 minutes. The time taken for the conc. to change from 0.1M to 0.025M is : (1) 30 min (2) 60 min (3) 7.5 min (4) 15 min (10.) The rate equation for the reaction 2A B C + → , is found to be r k A B =    . The correct statement in relation to this rection is that the (1) unit of k must be 1 sec− (2) value of k is independent of the initial concentrations of A and B (3) rate of formation of C is twice the rate of disappearance of A (4) 1/2 t is a constant (11.) The half-life of a first order chemical reaction is 6.93 minutes. The time required for the completion of 99% of the chemical reaction will be : (1) 23.03 minutes (2) 46.06 minutes (3) 460.6 minutes (4) 230.3 minutes (12.) Unit of rate constant for 2nd order reaction : (1) 1 mol− lit −1 time −1 (2) lit 1 moltime− (3) lit 1 mol− time −1 (4) 1 mollit− time −1 (13.) Decomposition of ozone to oxygen, 3 2 2O 3O → , follows the mechanism : 1 3 2 k 3 2 O O O(FastStep) O O 2O (Slowstep) + + ⎯⎯→ $$ The rate equation of the reaction is : (1)    1/2 3 2 r k O O = (2)     2 1 3 2 r k O O − − = (3)     2 1 O O 3 2 r k = (4)     2 1 3 2 r k O O − = (14.) What would be the rate equation of the reaction, A B+ → Products, If following data is collected experimentally : Exp. Conc. initial [a] Conc. initial [B] Initial rate (r) 1 0.1M 1.0M 3 2.1 10−  2 0.2M 1.0M 3 8.4 10−  3 0.2M 2.0M 3 8.4 10−  (1) 2 r k A = [ ] (2) 2 r k B = [ ] (3) 2 1 r k A B =   ] ]   (4) 1 1 r k A B =   ] ]  
(15.) The rate constants of two reactions are 1 2 k k  . How are the activation energies of these reactions, E1 and E2 related : (1) E E 1 2  (2) E E 1 2  (3) E E 1 2 = (4) Cannot be decided (16.) The ratio of time for 50% and 90% completion of a first order reaction is : (1) 1: 2 (2) 2:3 (3) 3:5 (4) 3:10 (17.) For the reaction, H g Br g 2HBr g 2 2 ( ) + → ( ) ( ) the experimental data suggest    1/2 2 2 rate H Br = k The molecularity and order of the reaction are respectively : (1) 1 1, 2 (2) 1,1 (3) 3 3 , 2 2 (4) 3 2, 2 (18.) The minimum energy required for a molecule to take part in a reaction is called : (1) threshold energy (2) nuclear energy (3) potential energy (4) kinetic energy (19.) Consider the reaction N g 3H g 2NH 2 2 3 ( ) + → ( ) the equality relationship between d NH  3  dt and d H 2  dt − is : (1) d NH d H  3 2  1   dt 3 dt = − (2) d NH d H  3 2  2   dt 3 dt + = − (3) d NH d H  3 2  2   dt 3 dt + = (4) d NH H  3 2    d dt dt = − (20.) Which of the following statement is not true for a first order reaction : (1) Graph between concentration and time(t) is a straight line with slope k 2.303 (2) Half life period is independent of initial concentration (3) Generally on increasing temperature half life period decreases (4) Unit of specific reaction rate is time −1 (21.) At constant volume, the decomposition reaction A g B g C g ( ) → + ( ) ( ) , follows first order kinetics and following data are obtained : Exp. No. time(sec.) Total pressure (atm)
1 0 0.50 2 69.32 0.75 The rate constant for the given reaction will be : (1) 1 1 10 sec − − (2) 2 1 10 sec − − (3) 3 1 10 sec − − (4) 4 1 10 sec − − (22.) Match the Column I with Column II and choose the correctoption : Column I Column II a. Zero order reaction i. 50% 0 1 t [ A]  b. First order reaction ii. 0 100% [A] t k = c. Second order reaction iii.involves atleast two reactants d. Pseudo unimolecular reaction iv   0 [ ] kt A A e− = (1) a-ii, b-iv, c-i, d-iii (2) a-iii, b-iv, c-ii, d-i (3) a-ii, b-i, c-iv, d-iii (4) a-iv, b-ii, c-i, d-iii (23.) In the Arrhenius plot of Ink Vs 1 T , the slope is 4 − 2 10 . The activation energy of the reaction is approx : (1) 83 kJ / mole (2) 166 kJ / mole (3) 249 kJ / mole (4) 332 kJ / mole (24.) A hypothetical reaction 2 2 X Y XY + → 2 follows the following mechanism i. 2 X X2 (fast) ii. 2 X Y XY Y + → + ( slow ) iii. X Y XY + (fast) the incorrect statement is : (1) The given reaction is nonelementary reaction (2) The order with respect to X2 is 1/ 2 (3) The order with respect to Y2 is 3/ 2 (4) None of these (25.) The following graph show how 1/2 t (half-life) of a reactant R changes with the initial reactant concentration 0 a . the order of the reaction will be: