Test: Zero Order & First Order Reactions - NEET MCQ

For the first order reaction, rate constant k is given by

kt = logC₀ - log C_t

where, C₀ is the intial concenration and C_t is the concentration at time t. Graph between log C_t and time t is

In a first order reaction, the concentration of the reactant decreases from 0.8 M to 0.4 M is 15 min. The time taken for the concentration to change from 0.1 M to 0.025 M is

For the First order reaction, concentration of the reactant after two averagelives is reduced to

The half-life period of a first order chemical reaction is 6.93 min. The time required for the completion of 99% of the chemical reaction will be (log2 = 0.3010)

[AIEEE 2009]

For the first order reaction,

A → Product

Q. The concentration of A changes from 0.1 M to 0.025 M in 40 min. The rate of the reaction when the concentration of A is 0.01 M is

[AIEEE 2012]

For the reaction,

A → Products,      

Concentration of A at different time intervals are given :

At 20 min, rate will be

For the first order reaction with, C₀ as the initial concentration and C at time  t, (C₀ - C) =

The radioisotope N-13 which has a half-life of 10 min is used to image organs in the body. If the injected sample has an activity of 40 μCi (microcurie), what is the activity after 30 min?

The following data were obtained during the first order decomposition of

2A(g) → B(g) + C(s)

at constant volume and at a particular temperature : 

Thus, rate constant is

A G .M. Counter is used to study the process of first order of radioactive disintegration. In the absence of radioactive substance A, it counts 3 dps (disintegration per second). When A is placed in G.M Counter it records 23 dps at the start and 13 dps after 10 min. It records x dps after next 10 min. Half-life period of A is y min. Thus, x and y are

Inversion of sucrose (C₁₂H₂₂O₁₁) is a first order reaction and is studied by measuring angle of rotation at different interval of time

r₀ = angle of rotation at the start, r_t = angle of rotation at time t
r_∞ = angle of rotation at the complete reaction

There is 50% inversion, when

Following radioactive disintegration follows first order kinetics :

Starting with 1 mol of A in a 1L flask at 300 K, pressure set up after two half-lifes is approximately

For the first order reaction T_av (average life), T₅₀ (half-life) and T₇₅ (time 75% reaction) are in the ratio of

For the first order reaction,

Following equations are given :

Select the correct equations.

Rate constant of a first order reaction (A → B) is 0.0693 min^-1. If initial concentration is 1.0 M, rate after 30 min is

Following reaction is pseudo-unimolecular w.r.t. C₆H₅N₂CI (A)

50 mL of 1M benzene diazonium chloride (A) is taken. After 1 h, 1.226 L of N₂ gas at 1 atm and 300 K is obtained. Thus, half-life of the reaction is (log 250 = 2.40) 

Minimum half-life of an isotope needed so that not more than 0.1 % of the nuclei undergo decay during a 3.0 h laboratory experiment is

Naturally occurring potassium consists of 0.01% at 40 K which has a half-life of 1.28 x 10⁹ yr. Activity of 1.00 g sample of KCl is

Direction (Q. Nos. 22-27) This section contains a passage describing theory, experiments, data, etc. Two questions related to the paragraph have been given. Each question has only one correct answer out of the given 4 options (a), (b), (c) and (d).

Passage l

Isotope of oxygen with mass number less than 16 undergoes β⁺ -emission. Assume an equimolar mixture of ¹⁴O and ¹⁵O, Also t₅₀ (¹⁴O) = 71s, t₅₀ (¹⁵O) = 124s.

Q. Ratio of rate constants of ¹⁴O to ¹⁵O is

Passage l

Isotope of oxygen with mass number less than 16 undergoes β⁺ -emission. Assume an equimolar mixture of ¹⁴O and ¹⁵O, Also t₅₀ (¹⁴O) = 71s, t₅₀ (¹⁵O) = 124s.

Q. Ratio of ¹⁴O to ¹⁵O left after 1.00 h is

Passage II

Consider acid-hydrolysis of ester which is first order reaction.

CH₃COOC₂H₅ + H₂O  CH₃COOH + C₂H₅OH

Kinetics is studied by titration of the acid with NaOH at a given time.
V₀ = Volume of NaOH at start, V_t = Volume of NaOH at time t, V_∞ = Volume of NaOH at the end of the complete hydrolysis.

Q. 
Rate constant k is given by

Passage II

Consider acid-hydrolysis of ester which is first order reaction.

CH₃COOC₂H₅ + H₂O  CH₃COOH + C₂H₅OH

Kinetics is studied by titration of the acid with NaOH at a given time.
V₀ = Volume of NaOH at start, V_t = Volume of NaOH at time t, V_∞ = Volume of NaOH at the end of the complete hydrolysis.

Q.

If ester is 50% hydrolysed, then 

Passage III

I, II and III are three vessels of equal volumes containing molecules of A as shown and in each A decomposes into products.

Q. 
Initial rate of decomposition of A will be in order in these three vessels as

Passage III

I, II and III are three vessels of equal volumes containing molecules of A as shown and in each A decomposes into products.

Q. 
Time of 50% decomposition is in order

Direction (Q. Nos. 28-30) This section contains 3 questions. When worked out will result in one integer from 0 to 9 (both inclusive).This section contains 3 questions, when worked out will result in an integer value from 0 to 9 (both inclusive)

Q. A radioactive element gets spilled over the floor of a room. Its half-life period is 30 days. If the initial activity is ten times the permissible value, it will be safer to enter the room after 10ⁿ days. What is the value of n?

For the first order reaction, variation of log₁₀(a - x)vs time (t) is shown below.

Q. 
Its half-life period is logx. What is the value of x?

For the first order reaction,

Q. 
If OA = 1.3010 then reactant left after 0.6021 min i s .......unit.