Chemical kinetics Questions and Answers

Mechanism of reaction 203 g 302 g can be given as 0 0 0 fast 03 0 0 20 slow Which of the following is correct rate law Or K 03 0 r K 0 0 Or K K 03 0 r K K 0 03 K

The molecular weight of O and SO are 32 and 64 respectively At 15 C and 150 mmHg pressure 9 256 litre of O contains N molecules The number of molecules in two litres of SO2 under the same

For a first order reaction AB the rate of reaction is 4x 10 mol L s when 4 2x 10 2 mol L What will be the value of rate constant when A is increased to 4 x 10 2 mol L 1 1 1 x 10 2 s 3 4 x 10 s 2 2 10 S 4 4 x 10 4 s

In a parallel chemical reaction A reactant change into products B C and D by using following stoichiometry and 1st order chemical kinetics what will be the overall rate of disappearance of A A B 2A C 3A 3 D Where K K2 and K3 are first order rate constants respectively A D d A dt B 3 A dt C 1 K K K A d A dt d A dt K A K A K A K A KIA K A K 2K 3K A

T C The rate constant for the decom at various temperatures are as follows 0 25 35 45 55 65 k s 7 9 x 10 7 3 5 x 10 5 1 35 x 10 4 5 0 x 10 4 1 5 x 10 3 4 9 x 10 Draw a graph and from it determine the activa tion energy of the reaction 1 5 The rate constants of a reaction at 500 K and 700 K are 0 02 s and 0 07 s respectively Calculate the values of E and A

1 In a reaction X Y product if concentration of X is increased to three times then rate increases by a factor of 3 and when the concentrations of both the reactants X and Y are tripled then rate increases by a factor of 9 The rate law for the reaction can be written as O Rate K X Y O Rate K X Y O Rate K X Y O Rate K X Y1

The decomposition of N O5 in CCl at 318K has been studied by monitoring the concentration of N O5 in the solution Initially the concentration of N O is 2 33 mol L and after 184 minutes it is reduced to 2 08 mol L The reaction takes place according to the equation 2 N O5 g 4 NO g O g 2 Calculate the average rate of this reaction in terms of hours minutes and seconds What is the rate of production of NO during this period

Consider the formation of Cu NH3 4 2 from Cu If the stepwise stability constant are represented C NH KINH KI CANH NH NH K KINH B NH KINH B NH NH NH K Ka If the values of log of K K2 K3 and the overall stability constant B of the complex are log K 4 log K 3 2 log K3 1 8 log B 11 then the value of at equilibrium is Cu NH Cu NH 0 01 times the concentration of NH3 100 times the concentration of NH3 250 times the concentration of Cu2 104 times the concentration of NH3

If rate constant for a first order reaction is 60 s the how much time will take to reduce the initial 1 concentration of the reactant to its 2 3 10 2 s S 4 6 x 10 s 6 9 10 2 S 16 th value

Which of the following statements is correct O Order of a reaction cannot be zero O Molecularity is applicable to elementary as well as complex reaction O Order is applicable to elementary as well as complex reactions O For complex reaction order is given by the fastest step

For a reaction A B C AH 40 kcal mol If Ea for the forward reaction is 30 kcal mol then E for the backward reaction is O 100 kcal mol O 50 kcal mol O 70 kcal mol 40 kcal mol

If rate constant for a first order reaction is 60 s then how much time will take to reduce the initial concentration of the 1 16 reactant to its th value 2 3 10 2 s 4 6 x 10 s 6 9 x 10 s 1 2 x 10 2

product if concentration of X is increased to three times then rate increases by a factor of 3 and when the concentrations of both the reactants X and Y are tripled then rate increases by a factor of 9 The rate law for the reaction can be written as In a reaction X Y Rate K X Y Rate K X Y Rate K X Y Rate K X Y 3

Half life period of a reaction is directly proportional to the initial concentration of the reactant This statement is correct for a O First order reaction O Third order reaction O Second order reaction O Zero order reaction

assuming reactions are of order 2 52 A radioactive element has atomic mass 90 amu and a half life of 28 years The number of disintegrations per second per g of the element is X 10 2

Q 51 The decomposition of N O into N and O in presence of gaseous argon follows second order kinetics with k 5 0 x 10 L mol s e parameters are kJ mol 29000 K T Arrhenius

In a bimolecular reaction the steric factor P was experimentally determined to be 4 5 Th correct option s following among is are This question has multiple correct options A Experimentally determined value of frequency factor is higher than that predicted by Arrhenius equation B The value of frequency factor is higher than that higher than that determined experimentally C The activation energy of the reaction is unaffected by the value of steric factor D Since P 4 5 the reaction will not proceed unless an effective catalyst is used

Question No 43 An aqueous solution containing one mole per litre each of Cu NO3 2 AgNO3 Hg2 NO3 2 Mg NO3 2 is being electrolysed by using inert electrodes The value of standard potential are 0 79V E Ag Ag E 0 80V E H H 0 34V and E 2 3V With increasing voltage the sequence of deposition of metals on the cathode will be Options Ag Hg Cu Mg Mg Mg

For a sequential reaction K 0 1386 min A B K 1 386 x 10 min 1 C D K 1 386 107 min K 6 93 10 0 min 1 Starting with E pure A initially concentration 1M what will be concentration of D after 10 min assuming steady state is obtained Question Type Single Correct Type 10 13 M

Select the rate law that corresponds to data shown for the following reaction 1994 A B products Exp B 1 0 035 2 0 070 3 0 035 0 070 A 0 012 0 024 0 024 4 0 012 a rate k B b rate k B 4 c rate k A B d rate k A B Initial rate 0 1 0 8 0 1 0 8

d The Pd isotope has a half life of 23 4 minutes If you have 5 000 kg of Pd when you start to take the Final Exam what mass of Pd in grams will you have two hours and 45 minutes later when you turn in your answers to the Final Exam on Canvas

3 10 Consider a one dimensional harmonic oscillator with vibrational frequency 5x 10 3 sec and mass 1x 10 23 g These are typical values for a diatomic molecule Find the average lifetime of the v 1 vibrational state

In a reaction between A and B the initial rate of reaction ro was measured for different initial concentrations of A and B as given below A mol L 1 0 20 B mol L 1 0 30 ro mol L s 5 07 x 10 5 What is the order of the reaction with respect to A and B 0 20 0 10 5 07 x 10 5 0 40 0 05 1 43 x 10 5

25 The mechanism of esterification in presence of acid catalyst H SO4 is proposed as follows O H k H fast CH3 C 0 H H O C H5 CH3 C a c P E P E VI I II O III CH3COH 1 OC H5 ks III IV R C III k s H fast IV H fast k O C H5 V Which of the following potential energy Vs reaction co ordinate diagram is consistent with given mechanism H fast V VI V VI O H 9 CH CO H II CH3 C OH b P E C H5OH slow k d P E C H5OH fast k2 k4 H O slow K4 H O fast p II IV V VI R C N III IV I II III 15 V VI fast k H O H CH3 C OH k3 fast 0 C H5 IV

A sample of air consisting of N and O was heated to 2500 K until the equilibrium N g O g 2NO g Was established with an equilibrium constant Kc 2 1 10 At equilibrium the mole of NO was 1 8 Estimate the initial composition of air in mole fraction of N2 and O2

For a reaction A B C product The rate of the reaction is given by Rate K A B C From the following data determine i The order with respect to A The order with respect to C Rate constant v a b C Initial concentrations mole dm B 0 005 0 005 0 010 0 005 A 0 010 0 010 0 010 0 020 C 0 010 0 015 0 010 0 010 ii iv The order with respect to B The over all order Initial rate mole dm s 5 0 10 5 5 0 10 5 2 5 10 14 x 10 5 Products ID B Products follow first order kinetic m

1 For a unimolecular reaction AB has rate constant K and for another unimolecular reaction C D has rate constant K If half life of first reaction is half of half life of second reaction then find Ea Ea will be 1 RT n2 3 RT n2 2 RT n2 4 1 RT n2

At 27 C it was observed during a reaction of hydrogenation that the pressure of hydrogen gas decreases from 2 atmosphere to 1 1 atmosphere in 75 minutes Calculate the rate of disappearance in M sec

Select the true statement about this diagram Potential Energy Reaction Coordinate The activation energy is raised when a catalyst is used This reaction is endothermic It is not possible to tell if the activation energy changes or if the reaction is endothermic or e The catalyst lowers the activation energy and the reaction is exothermic

X Y 2XY is given below 2 1 X X X fast ii X Y XY Y slow iii X Y XY fast The overall order of the reaction will be NEET 2017 2 2 4 1 5 1 1 3 O

54 When a biochemical reaction is carried out in laboratory outside the human body in absence of enzyme then rate of reaction obtained is 10 6 times the activation energy of reaction in the presence of enzyme is 1 6 RT 2 P is required 3 Different from E obtained in laboratory a

The rate constant of the production of 2B g by the reaction A g 2B g is 2 48 104 s 1 cemil 8st A 1 1 molar ratio of A to B in the reaction mixture is attained after 1 26 25 minute bns ito 2 27 25 minute 4 0 minute

For a first order Pseudo reaction CH COOC H H O CH COOH C H OH The net rate is given by dx Rate 4 x 104 CH3COOC2H5 2 x 104 CH3COOH C H5OH dt If the equilibrium constant of the reaction will be 2 x 10 x then the value of x

Decreasing order first having highest and then others following it of mass of pure NaOH in each of the aqueous solution i 50 g of 40 w W NaOH ii 50 mL of 50 w V NaOH d 1 2 g mL 1 g mL iii 50 g of 15 M NaOH d soln 1 i ii iii 2 iii ii i 3 ii iii i 4 ii i iii

For homogeneous gaseous reaction A B C D the initial pressure was Po while pressure after time t was P if P P The expression for the rate constant K is 1 K 2 K 3 K 2 303 log 2 p 2P 0 3P P t 2 303 t 2 303 t log log 3Po 0 2P P 0 Po Po P 2P

A compound X undergoes through first order Y decomposition in Y and Z as follows X The rate of reaction of X can be expressed as 1 K K X 3 K Z a Tower K 2 N 2 K Y 4 K K Y Z

Chemists commonly use a rule of thumb that an increase of 10 K in temperature doubles the rate of a reaction What must the activation energy be for this statement to be true for a temperature increase from 66 to 76 C Activation energy kJ mol

13 The reaction A B follows first order kinetics The time taken for 0 80 mole of A to produce 0 60 mole of B is 1 hour What is the time taker for conversion of 0 90 mole of A to produce 0 675 mole of B 1 1 hour 2 15 minuto 2 30 minute 4 5 minute

Determine the order of reaction A g 2 B g the vapour density of the system is determined at different stages of reaction occuring at constant temperature The reaction was started with pure A g Time min Vapour density of reaction mixture 0 42 10 35 20 30

The half life period of a gaseous substance undergoing thermal decomposition was measured for various initial pressure P with the following result P mm 5250 6300 11 2 min 136 112 5 Calculate the order of the reaction

In a reaction the initial concentration of the reactants increase four fold and the rate becomes eight times its initial value The order of the reaction is X ther value of 10 X is If the reaction is A B and elementary

DA KA Ag and A are the concentration at time t 0 and t respectively If 10 min were required for A to become dt in min is For a reaction with rate equation required to become A the time

For the reaction N O4 9 K rate of disappearance of NO will be 1 K N O4 K NO 2 2K N O4 2K NO 3 K NO K N O4 4 2K NO 2K N O4 2NO g the

171 Find activation energy Ea from following graph 1 and OP y R is ideal gas if slope tan 0 constant P In K O 1 R 2 R 3 R y 4 R y 1 T 172 The reduction potential of hydrogen electrode at pOH 4 is 1 0 59 V 2 0 59 V 3 0 236 V

The temperature coefficient of the rate of a reaction is 2 3 How many times will the rate of reaction increase if the temperature is raised by 25 K 2 3 25

2 51 A drop of solution volume 0 05 ml contains 3 0 x 10 6 mole of H If the rate constant of disappearance of H is 1 0 x 107 mole 1 s It would take for H in drop to disappear in X 10 s

For the reaction R P the concentration of reactant changes from 0 03 M to 0 02 M in 25 minutes Calculate the average rate of reaction using units of time both in minutes and seconds

Chem Section A This section contains 35 SINGLE CO questions Each question has 4 choic Read More Copper matte contains Cu 0 and Fe203 O Cu S and Fes Cu 0 and Cu S

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 20 30 O 23 03 minutes O46 06 minutes O 460 6 minutes 030 3 minuton

The activation energy of a certain reaction is 35 1 kJ mol At 26 C the rate constant is 0 0180s temperature in degrees Celsius would this reaction go twice as fast Express your answer with the appropriate units At what