Factors Affecting Rate of Reaction

Q. When 20g of CaCo3 were put into 10 litre flask and heated to 800°C, 30% of CaCo3 remained unreacted at equilibrium K_p for decomposition of CaCo3 will be -------
1)1.145atm 2)1.231 atm
2)2.146 atm 4)3.145 atm

Q. The rate of gaseous reaction is given by the expression $k\left[A\right]\left[B\right]$. If the volume of the reaction vessel is suddenly reduced to $1/4^{th}$ of the initial volume, the reaction rate relating to original rate will be:

1. $1/10$
2. $1/8$
3. $8$
4. $16$

Q.

The activation energy for the reaction

2HI_(g) → H₂ + I_2(g)

is 209.5 kJ mol⁻¹ at 581K. Calculate the fraction of molecules of reactants having energy equal to or greater than activation energy?

Q.

Which of the following statements is incorrect for the order of reaction:

1. Order of reaction is not affected with the stoichiometric coefficients of the reactants.

2. Order of reaction is equal to the sum of the power of concentration terms in differential rate law.

3. Order of a reaction cannot be fractional.

4. Order of reaction can be determined experimentally.

Q. For first order homogeneous gaseous reaction A → 2B + C, the initial pressure was $P_0$ while total pressure at time 't' was $P_t$. The expression for the rate constant $k$ in terms of $P_0,P_t$ & t is:

1. $k=\frac{2.303}{t}log\left(\frac{2P_0}{3P_0-P_t}\right)$
2. $k=\frac{2.303}{t}log\left(\frac{2P_0}{2P_t-P_t}\right)$
3. $k=\frac{2.303}{t}log\left(\frac{P_0}{P_0-P_t}\right)$
4. None of these

Q.

If 0.5 moles of BaCl2 is mixed with 0.2 moles ofNa3PO4 the maximum number of moles ofBa3(PO4)2 that can be formed

Q.

In ionic equilibrium when dilution increases why degree of dissociation increases?

Q.

The rate of a reaction quadruples when the temperature changes from

293 K to 313 K. Calculate the energy of activation of the reaction assuming

that it does not change with temperature.

Q.

If α is the degree of dissociation of Na₂SO₄, the van't Hoff factor , i , used for calculating the molecular mass is

1. 1 - α

2. 1 - 2α

3. 1 + α

4. 1 + 2α

Q. For reaction,
$aA+bB\to \text{Product}$
$\text{Rate of reaction}=K{\left[A\right]}^a{\left[B\right]}^b$.
If concentration of 'A' is doubled, rate is increased to four times. If concentration of B is made four times, rate is doubled. What is relation between rate of disappearance of A and that of B?

1. $-\left\{\frac{d\left[A\right]}{dt}\right\}=-\left\{\frac{d\left[B\right]}{dt}\right\}$
2. $-\left\{\frac{d\left[A\right]}{dt}\right\}=-\left\{\frac{4d\left[B\right]}{dt}\right\}$
3. $-\left\{\frac{4d\left[A\right]}{dt}\right\}=-\left\{\frac{d\left[B\right]}{dt}\right\}$
   
4. None of these

Q.

Calculate the n factor of Fe2O3 in the reaction

Fe2O3 ----: Fe + O2

Q.

Why does the rate of a reaction increase with rising in temperature?

Q.

If 9g of H₂O is electrolysed completely with 50% current efficiency, then how much O2 will be formed at STP?

Q. Decomposition of both $A_2\left(g\right)$ and $B_3\left(g\right)$ follows first order kinetics as:
$A_2\left(g\right)\stackrel{k_1}{\to }2A\left(g\right);k_1\left(perh{r}^{-1}\right)=e^{\frac{14000\left(/J\right)}{RT}+5}{B}_3\left(g\right)\stackrel{k_2}{\to }3B\left(g\right);k_2\left(perh{r}^{-1}\right)=e^{\frac{20000\left(/J\right)}{RT}+10}$
Where $k_1$ and $k_2$ are the rate constants with respect to disappearance of $A_2$ and $B_3$, respectively.
One mole of each of $A_2\left(g\right)$ and $B_3\left(g\right)$ are taken in a $100\text{L}$ evacuated flask and at some temperature at which they start decomposing at the same rate. Select incorrect statement(s):
(Here $A_2$ and $B_3$ gases are nor reacting ideal gases)

1. The temperature at which the rections are performed is $\frac{1200}{R}$
2. At any instant, $\left(\frac{P_{A_2}}{P_{B_3}}\right)$ will be constant and equal to $1$ where $P_{A_2}=$ Partial pressure of $A_2$ and $P_{B_3}=$ Partial pressure of $B_3$
3. At some instant, the total pressure of all the gases may be less than $0.2$ atm
4. At any instant, $\left(\frac{P_A}{P_B}\right)$ will be constant and equal to 1 where $P_A=$ Partial pressure of $A$ and $P_B=$ Partial pressure of $B$

Q. The gaseous decomposition reaction:$A\left(g\right)\to 2B\left(g\right)+C\left(g\right)$, is observed to be first order over the excess of liquid water at ${25}^{o}C$ at constant volume. It is found that after 10 minutes, the total pressure of the system is $188torr$ and at completion of reaction the pressure is $388torr$. Calculate the rate constant of the reaction in $h{r}^{-1}$. The vapour pressure of $H_{2}O$ at ${25}^{o}C$ is $28torr$.
Take
$ln1.2\approx 0.18$

1. 0.018
2. 1.08
3. 0.24
4. 0.12

Q. Decomposition of $3A\left(g\right)\to 2B\left(g\right)+2C\left(g\right)$ follows first-order kinetic. Initially, only $A$ is present in the container. The pressure developed after $20\text{min}$ and infinite time are $3.5$ and $4\text{atm}$, respectively. Which of the following is true?

1. $t_{50\text{\%}}=20\text{min}$
2. $t_{75\text{\%}}=40\text{min}$
3. $t_{99\text{\%}}=64/3\text{min}$
4. $t_{87.5\text{\%}}=60\text{min}$

Q. Peptization is a :

1. Process of converting soluble particles to form coloidal solution
2. Process of converting a colloidal solution into precipitate
3. Process of converting precipitate into colloidal solution
4. Process of bringing colloidal molecule into solution

Q. For a reaction $A+2B\to C+D$, the following data were obtained

The correct rate law expression will be

1. $\text{Rate}=k\left[A\right][B{]}^2$
2. $\text{Rate}=k\left[A{]}^2\right[B{]}^2$
3. Rate = k [A] [B]
4. $\text{Rate}=k\left[A{]}^2\right[B]$

Q. The Half Life period of zero order reaction was found to be 10 minutes when initial concentration was 1 mole per litre what will be the half life period if initial concentration is made to mole per litre

Q. The concentration of a reactant X decreases from 0.1 M to 0.025 M in 40 minutes. If the reaction follows I order kinetics, the rate of the reaction when the concentration of X is 0.01 M will be

1. $3.47\times {10}^{-4}Mmi{n}^{-1}$
2. $1.73\times {10}^{-4}Mmi{n}^{-1}$
3. $1.73\times {10}^{-5}Mmi{n}^{-1}$
4. $3.47\times {10}^{-5}Mmi{n}^{-1}$

Q. The gas phase decomposition of dimethyl ether follows first order kinetics.
$C{H}_{3}OC{H}_3\left(g\right)\to C{H}_4\left(g\right)+H_2\left(g\right)+CO\left(g\right)$
The reaction is carried out in a constant volume container at ${500}^{\circ }\text{C}$ and has a half life of $30.1$ minutes. Initially, only dimethyl ether is present at a presure of $0.396\text{atm}$. What is the total pressure (in $\text{atm}$ after $12$ minutes? Assume ideal gas behavior. (Give your answer upto two decimal)
(Given: ${10}^{0.12}=1.32$)

Q.

Sn2 reaction depend on the what all factors

Q. 33. If the initial concentration of reactants is reduced to half in a reaction, then the half life of a reaction becomes two times. The order of the reaction is 0 1 2 3

Q. 41. In Arrhenius equation for certain reaction, the value of A and E (activation energy) are 4\ast10^{13}S^{-1} and 98.6 kJ mol^{-1} respectively. If the reaction is of first order, then at what temperature will its half life period be 10 minutes? log 2.88=0.4594 1.350.5 K 2.270.2 K 3.453.6K 4.311.5K

Q. What is the rate of reaction for a bimolecular elementary reaction?

1. $Z_{AB}{e}^{(}\frac{-E_a}{RT})$
2. $Z_{AB}{e}^{(}\frac{E_a}{RT})$
3. $-Z_{AB}{e}^{(}\frac{-E_a}{RT})$
4. $-Z_{AB}{e}^{(}\frac{E_a}{RT})$

Q. 67. At 27^° C in presence of catalyst activation energy of a reaction is lowered by 2 kcal, then the rate of reaction increases by (1) 7 times (2) 14 times (3) 21 times (4) 28 times

Q. At 227^oC, the presence of a catalyst lowers the activation energy by 4606 cal. The rate of reaction will be increased by? a. 10 b. 2 c. 100 d. 100

Q. For the given gaseous reaction $A⟶2B+C$ pressure after sufficient time was found to be $300\text{mm Hg}$ and after time $2.303\text{sec}$, it was found to be $200\text{mm Hg}$, the half-life is (Given log 2 = 0.3010)

Q.

Observation no.	Time (in min)	$P_x\left(inmmHg\right)$
1	0	800
2	100	400
3	200	200

At constant temperature and volume, $X$ decomposes according to first order kinetics as follows:
$2X\left(g\right)\to 3Y\left(g\right)+2Z\left(g\right)$
where $P_x$ is the partial pressure of $X$.

Which of the following statements is true for the given reaction?

1. Rate constant of reaction is $6.93\times {10}^{-3}{min}^{-1}$
2. At $200min$, 75% of the reaction completes
3. When $P_x=700mmHg$, the total pressure of the system is $950mmHg$
4. All of the above

Q.

Freshly prepared precipitate sometimes gets converted to colloidal solution by

1. peptisation
2. coagulation
3. electrolysis
4. diffusion