Zero Order Reaction

Q. If $99\%$ of a first order reaction was completed in $32$ minutes then, when $99.9\%$ of the reaction will complete:

1. $50\text{min}$
2. $46\text{min}$
3. $48\text{min}$
4. $49\text{min}$

Q.

In $\mathrm{A}$ reaction; $2\mathrm{A}\to \mathrm{Products}$, the concentration of $\mathrm{A}$ decreases from $0.5\mathrm{mol}{\mathrm{L}}^{-1}\mathrm{to}0.4\mathrm{mol}{\mathrm{L}}^{-1}$ in 10 minutes. Calculate rate during this interval.

Q.

The major product $\left[\mathrm{C}\right]$ of the following reaction sequence will be:

1. 

2. 

3. 

4. 

Q. 1. The value of rate constant depends upon A-temperature B-concentration C-catalyst D-both a and c

Q.

The decomposition of $N{H}_3$ on platinum surface is zero order reaction. What are the rates of production of N_2 and H_2 if $k=2.5\times {10}^{-4}mo{l}^{-1}L{s}^{-1}$ ?

Q. The decomposition of formic acid on gold surface follows first order kinetics. If the rate constant at $300\text{K}$ is $1.0\times {10}^{-3}{\text{s}}^{-1}$ and the activation energy $E_a=11.488{\text{kJ mol}}^{-1}$, the rate constant at $200\text{K}$ is $\times {10}^{-5}{\text{s}}^{-1}$.(Round off to the nearest Integer).

Q.

For a general reaction $A\to B$, the plot of concentration of A vs time is given in the figure. Answer the following questions on the basis of this graph. (i) What is the order of the reaction? (ii) What is the slope of the curve? (iii) What are the units of rate constant?

Q. Half life of a first order reaction is 10 min. What % of reaction will be completed in 100 min ?
${10}^{3.009}\approx 1020.9$

1. 25%
2. 99.9%
3. 75%
4. 80%

Q.

The rate constant of a first order reaction, whose half-life is 480 seconds, is

1. 1.44 x 10^-3 s^-1

2. 0.72 x 10^-3 s^-1

3. 2.88 x 10^-3 s^-1

4. 1.44 s^-1

Q. a 1st order reaction graphs between t1/2 & concentration i

Q. At 300 K, the half life of a sample of a gaseous compound initially at 1 atm is 100 sec. When the initial pressure at same temperature is 0.5 atm the half life is 50 sec, the order of the reaction is x. What is the value of x?

Q.

For a zero order reaction will the molecularity be equal to zero? Explain.

Q. For the given reaction:
$N{O}_2+F_2\to 2N{O}_{2}F$
Mechanism involves two steps:
$\text{I:}N{O}_2+F_2\to 2N{O}_{2}F+F\left(Slow\right)$
$\text{II :}N{O}_2+F\to N{O}_{2}F\left(Fast\right)$
Choose the correct option(s):

1. Molecularity of $I$ step is 2
2. $II$ is the rate determining step.
3. $I$ is the rate determining step.
4. Molecularity of $I$ step is 1

Q. If rate constant of a reaction is 9.212 × 10^–4 s^–1, then the time required for the completion of 75% of the reaction will be

यदि एक अभिक्रिया का वेग नियतांक 9.212 × 10^–4 s^–1 है, तो अभिक्रिया के 75% पूर्णता के लिए आवश्यक समय होगा

1. 10 min
   
   10 मिनट
2. 15 min
   
   15 मिनट
3. 20 min
   
   20 मिनट
4. 25 min
   
   25 मिनट

Q. The concentration of R in the reaction: R→ P was measured as a function of time and the following data is obtained:\lbrack R\rbrack (molar)1.0, 0.75, 0.40, 0.10 t(min.)0.0 , 0.05 , 0.12, 0.18.The order of the reaction is.(1) Zero(2) 1(3) (4) 4

Q.

In the case of a zero-order reaction, the ratio of time required for $75\%$completion to $50\%$ completion is?

Q.

The rate constant of the reaction $A\to B$ is $0.6\times {10}^{-3}$ mole per second. If the concentration of B after 20 min is:

1. 0.36 M

2. 1.08 M

3. 3.60 M

4. 0.72 M

Q.

Write the rate equation for the reaction $2A+B⟶C$ if the order of the reaction is zero.

Q. For a first order reaction, the time required for $99.9\%$ of the reaction to take place is $n$ times the time required for half of the reaction to take place.
What is the value of $n$ to the nearest integer?
(Take $lo{g}_{10}2=0.3$)

1. $2$
2. $10$
3. $0.5$
4. $100$

Q.

Consider the kinetic data given in the following table for the reaction A + B + C → Product

Ex. No.	[A]	[B]	[C]	Rate of reaction
1.	$0.2$	$0.1$	$0.1$	$6\times {10}^{-5}$
2.	$0.2$	$0.2$	$0.1$	$6\times {10}^{-5}$
3.	$0.2$	$0.1$	$0.2$	$1.2\times {10}^{-4}$
4.	$0.3$	$0.1$	$0.1$	$9\times {10}^{-5}$

When [A] $=0.15$

[B] $=0.25$

[C] $=0.15$

Rate of reaction is $Y\times {10}^{-5}m/s$. Find $\mathrm{Y}$.

Q.

In the reaction A + B → Products, if B is taken in excess, then it is an example of

1. Second order reaction

2. Zero order reaction

3. Pseudo first order reaction

4. First order reaction

Q. In a first-order reaction, the concentration of the reactant, decreases from $0.8M$ to $0.4M$ in $15\text{minutes}$ half life. The time taken for the concentration to charge from $0.1M$ to $0.025M$ is:

1. $30minutes$
2. $15minutes$
3. $7.5minutes$
4. $60minutes$

Q. For oxidation of iron , 4Fe + 3O_{2 ---->} 2Fe₂O₃ , inspite of negative entropy change of this reaction why is the reaction spontaneous ?

Entropy change : - 549.4J/k mol

Enthalpy of reaction : -1648 x 10³ J/mol

Q.

Derive an expression to calculate time required for completion of zero order reaction.

Q. A first order reaction completes $50$% in $69.3$ minute. How much time it will take for $90$% completion?

1. $230.3minutes$
2. $115.15minutes$
3. $460.6minutes$
4. None of these

Q. A reaction :
aA $\to$ product
follows zero order kinetics. The concentration of A with respect to time (t) is given as:

1. $\left[A_0\right]$ = $\left[A\right]-kt$
2. $\left[A\right]$ = $\left[A_0\right]+kt$
3. $\left[A\right]$ = $\left[A_0\right]-\frac{kt}{a}$
4. $\left[A\right]$ = $\left[A_0\right]-akt$

Q.

At high pressure the following reaction is zero order.
$2N{H}_3\left(g\right)\underset{Platiniumcatalyst}{\overset{1130K}{\to }}{N}_2\left(g\right)+3H_2\left(g\right)$ Which of the following options are correct for this reaction?
(a)Rate of reaction = Rate constant
(b)Rate of the reaction depends on concentration of ammonia
(c)Rate of decomposition of ammonia will remain constant until ammonia disappears completely
(d)Further increase in pressure will change the rate of reaction

Q. How does the graph (concentration vs time) of a zero order reaction look like?

1. 
2. 
3. 
4. 

Q. Which of the following expressions is correct for zero order and first order respectively (where $a$ is initial concentration)

1. $t_{1/2}\propto a;t_{1/2}\propto \frac{1}{a}$
2. $t_{1/2}\propto a;t_{1/2}\propto a^0$
3. $t_{1/2}\propto a^0;t_{1/2}\propto a$
4. $t_{1/2}\propto a;t_{1/2}\propto \frac{1}{a^2}$

Q.

Which of the following statements is incorrect about rate of reaction ?

1. The unit of rate constant is mol L^-1 s^-1

2. It can be expressed as the rate of decrease in concentration of any one of the reactants.

3. It can be expressed as the rate of decrease in concentration of any one of the products

4. It can be expressed as the rate of increase in concentration of any one of the products