12tth Chemistry Important 1 Marks Chemical Kinetics
One Mark Study Material Unit wise as per reduced syllabus (2021-22)
TN 12tth Chemistry Important 1 Marks Chemical Kinetics. 12th Chemistry Important Questions Chapter 6. +2 Chemistry Important 2 Marks, 3 Marks, 5 Marks Questions Based on reduced Syllabus 2021-2022. 12th Free Online Test (MCQs). HSC 12th Chemistry Revision Test Important Questions. 12th Tamil Full Guide.
- 1. The half-life period of a radioactive element is 140 days. After 560 days. 1g of element will be reduced to ( 1/16 g)
- 2. After 2 hours a radioactive substance becomes (1/16)th of original amount. The half-life (in minutes) is 30 minutes
- 3. A zero order reaction X gives product, with an initial concentration 0.02M has a half-life of 10 minutes if one starts with concentration 0.04M, then the half- life is 20 minutes.
- 4. For a first order reaction A gives B the rate constant is x min-1. If the initial concentration of A is 0.01M the concentration of A after one hour is given by the expression. ( 1x 10-2)e-60x.
- 5. For a first order reaction A give product with initial concentration x mol,L-1 has a half-life period of 2.5 hours. For the same reaction with initial concentration (x/2) mol.L-1 the half –life is 2.5 hours.
- 6. The decomposition of phosphine(PH3) on tungsten at low pressure is a first order reaction. It is because the rate is independent of the surface coverage.
- 7. The addition of a catalyst during a chemical reaction alters the following quantities is Activation energy
- 8. The rate constant of a reaction is 5.8 x 10-2s-1. The order of the reaction is
- 9. During the decomposition of H2O2 to give dioxygen, 48g O2 is formed per minute at certain point of time. The rate formation of water at this point is 3.0 mol.min-1
- 10. If the initial concentration of the reactant is doubled , the time for half reaction is also doubled. Then the order of the reaction is Zero
- 11. For any reaction if we plot a graph between time ‘t’ and log(a-x), a straight line is obtained. The order of the reaction is First order
- 12. The half-life of paracetamol with in the body is 2.5 hours
- 13. t1/2 of the reaction increase with increase initial concentration of the reaction means the order of the reaction will be Zero order
- 14. The overall order of the reaction 5Br- + 6H+ is 4
- 15. What is the order of a reaction which has a rate expression rate = K[A]1/2[B]-1
- 16. The no .of. molecules of the reactant taking part in a single step of the reaction is indicative of molecularity of a reaction
- 17. For an elementary reaction 2A + B → C + D the molecularity is Three
- 18. If the unit rate and rate constant are same, then the order of the reaction is
- 19. If the initial concentration of the reactants is doubled, then rate is increased by four times of initial rate.
20. Acid hydrolysis of ester is an example of pseudo first order reaction.
- 21. When Ea of the reaction zero then the rate constant of the reaction is equal to
- 22. Activation energy is equal to Threshold energy x energy of colliding molecules
- 23. In a second order reaction, if one of the concentrations is excess, the order of the reaction is Pseudo first order reaction.
- 24. If the activation energy is high, then the rate of reaction is fast
- 25. All radioactive transformation follows First order Kinetics
- 26. The half-life period of first order reaction in 10 seconds. What is the time required for completion of that time? 100 seconds
- 27. The hydrolysis of ethyl acetate: CH3COOC2H5 + H2O / H+ → CH3COOH + C2H5OH belong to this reaction pseudo first order reaction.
- 28. The unit of zero order rate constant is mole.litre-1sec-1
- 29. The addition of catalyst during a chemical reaction alters which of the following quantities is Activation energy
- 30. What will be the rate constant of a First order reaction, if its half-life is given to be 20 minutes? 3.47 x 10-2min-1
- 31. How much time will be taken for 20gm to reduce 5g? [ R = 2 x 10-3s-1(First order reaction)] 693.1 s
- 32. A first order reaction is 50% completed in 1.26 x 1014. How much time would take for 100% completion? Infinite
- 33. For the second order reaction t1/2 𝛼 1/a
- 34. The excess energy which a molecule must posses to become active is known as
- 35. Arrhenius equation is k = Ae-Ea/RT
- 36. The term A in Arrhenius equation is called as Frequency factor
- 37. The half-life period of a first order reaction is 10 minutes then its rate constant is 6.932 x 10-2min-1
- 38.2N2O5 → NO2 + O2, d[N2O5]/dt = K2[N2O5] & d[O2]/dt =K3[N2O5], the
relation between K1,K2 & K3 is 2K1=K2=K3
- 39. What would be the rate of disappearance of oxygen, if the rate of formation of nitric oxide (NO) is 3.6 x 10-3 mol.L-1 s-1? 4.5 x 10-3mol.L-1s-1
- 40. For the reaction, 2N2O5 → 4NO2 + O2 the correct statement is Rate of formation O2 is 0.5 times rate of disappearance of N2O5
- 41. Molecularity of a reaction can be zero this statement is not correct.
- 42. Half – life period formula is t1/2 = 0.6932/k.
- 43. If n≠1 integration of above equation between [Ao] & [A] at time = 0 & t = t respectively gives 1/[A]n-1 – 1/[Ao]n-1 =(n-1)kt. 47. Integrated rate law for a first order reaction formula is K = 2.303/t log([Ao]/[A]).
- 44. Isomerization of cyclopropane to propene is an example for First order reaction.
- 45. Photochemical reaction between H2 and Cl2 is an example for zero order reaction.
- 46. Half-life for nth order reaction involving reactant A and n≠ 1 is t1/2 = 2n-1 – 1