Q1. In a 1st order reaction, reactant concentration C varies with time t as
Solution
B
B
Q2.Rate equation for a second order reaction is:
Solution
dx/dt=K(a-x)^2 is differential form of II order. Integrate it to get (c).
dx/dt=K(a-x)^2 is differential form of II order. Integrate it to get (c).
Q3. The rate constant (k^' ) of one of the reaction is found to be double that of the rate constant (k^'') of another reaction. Then the relationship between the corresponding activation energies of the two reaction (E_a^' and E_a^'' ) can be represented as
Solution
∵ Rate constant (k^' )> rate constant (k^(' ')) Greater the rate constant lesser will be the activation energy ∴E_a^'
∵ Rate constant (k^' )> rate constant (k^(' ')) Greater the rate constant lesser will be the activation energy ∴E_a^'
Q4. Which increases on increase of temperature?
Solution
The collision frequency (Z)and rate contant(k) increase on increase of temperature. With the increase in temperature, the average kinetic energy of the molecules increases and this leads to an increase in number of collisions per unit time (Z). The rate constant (k) of a reaction is also increases with increase of temperature.
The collision frequency (Z)and rate contant(k) increase on increase of temperature. With the increase in temperature, the average kinetic energy of the molecules increases and this leads to an increase in number of collisions per unit time (Z). The rate constant (k) of a reaction is also increases with increase of temperature.
Q5.Find the two third life (t_(1/2))of a first order reaction in which k=5.48×〖10〗^(-14)per second
Solution
Let ,initial concentration=a Final concentration=a- 2/3 a= a/3 t_(2/3)=2.303/k log a/(a/3) =2.303/(5.48×〖10〗^(-14) ) log3 =2.01×〖10〗^13 s
Let ,initial concentration=a Final concentration=a- 2/3 a= a/3 t_(2/3)=2.303/k log a/(a/3) =2.303/(5.48×〖10〗^(-14) ) log3 =2.01×〖10〗^13 s
Q6. Which one is not correct?
Solution
The rate of zero order reaction is independent of the concentration of the reactants or the concentration of the reactant do not change with time. Thus, the rate of reaction remains constant. dx/dt=k(a-x)^0⇒dx/dt=k Or Rate=k
The rate of zero order reaction is independent of the concentration of the reactants or the concentration of the reactant do not change with time. Thus, the rate of reaction remains constant. dx/dt=k(a-x)^0⇒dx/dt=k Or Rate=k
Q7. For a first order reaction the graph log〖 [A]〗 vs t is given below
x is equal to
x is equal to
Solution
Q8.2N_2 O_5 (g)→4NO_2 (g)+O_2 (g)
What is the ratio of the rate of decomposition of N_2 O_5 to rate of formation of O_2 ?
Solution
Q9.Unit of frequency factor (A) is
Solution
Unit of A depends on unit of k.
Unit of A depends on unit of k.
Q10. If the volume of the vessel in which the reaction 2NO+O_2→2NO_2 is occurring is diminished to 1/3rd of its initial volume. The rate of the reaction will be increased by
Solution
As we know that, rate of reaction is directly proportional to concentration of reactant and inversely proportional to the volume of vessel. i.e.,concentrationα∝n/v For a given reaction, 2NO(g)+O_2 (g)⇌2NO_2 (g) Rate of reaction=k[NO]^2 [O_2] If volume of vessel is reduced by 1/3 rd of its initial value, then concentration of compound is increase by 3 times. Hence, the rate of reaction will be increased by 27 times.
As we know that, rate of reaction is directly proportional to concentration of reactant and inversely proportional to the volume of vessel. i.e.,concentrationα∝n/v For a given reaction, 2NO(g)+O_2 (g)⇌2NO_2 (g) Rate of reaction=k[NO]^2 [O_2] If volume of vessel is reduced by 1/3 rd of its initial value, then concentration of compound is increase by 3 times. Hence, the rate of reaction will be increased by 27 times.
