Rate of Reaction

Q.

Reaction $\mathrm{A}+\mathrm{B}\to \mathrm{C}+\mathrm{D}$ follows the following rate law: $\mathrm{rate}=\mathrm{k}{\left[\mathrm{A}\right]}^{1/2}{\left[\mathrm{B}\right]}^{1/2}$​. Starting with initial conc. of $1\mathrm{M}$ of A and B each, what is the time taken for the concentration of A to become $0.25\mathrm{M}$? $(\mathrm{Given}:\mathrm{k}=2.303\times {10}^{-3}\mathrm{s})$

Q.

For the reaction, $N_2{O}_5\left(g\right)\to N{O}_2\left(g\right)+\frac{1}{2}{O}_2\left(g\right)$ The value of rate of disappearance of $N_2{O}_5$ is given as $6.25\times {10}^{-3}mol{L}^{-1}{s}^{-1}.$ The rate of formation of $N{O}_2$ and $O_2$ is given respectively as:

1. $1.25\times {10}^{-2}mol{L}^{-1}{s}^{-1}and3.125\times {10}^{-3}mol{L}^{-1}{s}^{-1}$

2. $6.25\times {10}^{-3}mol{L}^{-1}{s}^{-1}and3.125\times {10}^{-3}mol{L}^{-1}{s}^{-1}$

3. $1.25\times {10}^{-}2mol{L}^{-1}{s}^{-1}and6.25\times {10}^{-3}mol{L}^{-1}{s}^{-1}$

4. $6.25\times {10}^{-3}mol{L}^{-1}{s}^{-1}and6.25\times {10}^{-3}mol{L}^{-1}{s}^{-1}$

Q.

Let us dive into the land of Westeros!

When the dragons ofDanaerysthe dragon queen burn their victims, the following reaction takes place:

$2C+O_2⟶2C{O}_2$

The average rate of reaction could be expressed as?

1. All of the above
2. 
3. 
4. 

Q.

For the non - stoichiometric reaction, 2A+B $\to$ C + D, the following kinetic data were obtained in three separate experiments, all at 298 K.

$\begin{array}{cccc}& Initial& Initial& Initialrateof\\ & concentration& concentration& formationofC\\ & \left[A\right]& \left[B\right]& \left(mol{L}^{-1}{s}^{-1}\right)\\ \left(i\right)& 0.1M& 0.1M& 1.2\times {10}^{-3}\\ \left(ii\right)& 0.1M& 0.2M& 1.2\times 1^{-3}\\ \left(iii\right)& 0.2M& 0.1M& 2.4\times {10}^{-3}\end{array}$

The rate law for the formation of C is

1. $\frac{dC}{dt}=k\left[A\right]\left[B\right]$

2. $\frac{dC}{dt}=k\left[A{]}^2\right[B]$

3. $\frac{dC}{dt}=k\left[A\right][B{]}^2$

4. $\frac{dC}{dt}=k\left[A\right]$

Q.

An astronaut gets thirsty on the moon. So, he prepares water by mixing hydrogen and oxygen. Will the mass ratio of hydrogen to oxygen present in the water on moon will be same as that on the earth?

1. It will be different.

2. It will be the same.

3. On moon the water will have lighter mass than on the earth.

4. On moon the water will have heavier mass than on the earth.

Q. For the reaction 2A + B + C $\to A_{2}B$ + C the rate law is found to be Rate =k[A][B]${}^2$ with $k=2\times {10}^{-6}mo{l}^{-2}{L}^2{s}^{-1}$
The initial rate of reaction with $\left[A\right]=0.1mol{L}^{-1},\left[B\right]=0.2mol{L}^{-1}and\left[C\right]=0.8mol{L}^{-1}$ is

1. $6.4\times {10}^{-8}mol{L}^{-1}{s}^{-1}$
2. $4\times {10}^{-3}mol{L}^{-1}{s}^{-1}$
3. $8\times {10}^{-9}mol{L}^{-1}{s}^{-1}$
4. $4\times {10}^{-7}mol{L}^{-1}{s}^{-1}$

Q. The rate of reaction between two reactants A and B decreases by a factor of 4, if the concentration of reactant B is doubled. The order of this reaction with respect to reactant B is [CBSE AIPMT 2005]

1. 1
2. - 1
3. - 2
4. 2

Q.

Which of the following is an example of double displacement reaction?
(i) $C{O}_2\left(g\right)+H_2\left(g\right)\to CO\left(g\right)+H_{2}O\left(g\right)$
(ii) $P_4{O}_{10}\left(s\right)+6H_{2}O\left(l\right)\to 4H_{3}P{O}_4\left(aq\right)$
(iii) $H_2+O_2\to H_{2}O$​​​​​​​
(iv) $CoC{l}_2\left(aq\right)+N{a}_{2}C{O}_3\left(aq\right)\to CoC{O}_3\left(aq\right)+2NaCl\left(aq\right)$​​​​​​​

1. (iii)

2. (ii)

3. (iv)

4. (i)

Q.

(a) Derive the unit of rate constant for a first order reaction. (b) The activation energy of a reaction is 94.14kJ mol-1 and the value of rate constant at 313K is 1.8×10-5 s-1. Calculate frequency factor A.

Q. The rate at which a substance reacts depends upon:

1. Atomic weight
2. Atomic number
3. Molecular weight
4. Active mass

Q. “He was sure the crowd did too.” Explain the meaning of this statement.