11
MCQ (Single Correct Answer)
Which of the following statements is correct?
A
The rate of a reaction decreases with passage of time as the concentration of reactants decreases
B
The rate of a reaction is same at any time during the reaction
C
The rate of a reaction is independent of temperature change
D
The rate of a reaction decreases with increase in concentration of reactant (s)
12
MCQ (Single Correct Answer)
Which of the following expressions is correct for the rate of reaction given below?
$$5 \mathrm{Br}^{-}(a q)+\mathrm{BrO}_3^{-}(a q)+6 \mathrm{H}^{+}(a q) \rightarrow 3 \mathrm{Br}_2(a q)+3 \mathrm{H}_2 \mathrm{O}(l)$$
A
$\frac{\Delta\left[\mathrm{Br}^{-}\right]}{\Delta t}=5 \frac{\Delta\left[\mathrm{H}^{+}\right]}{\Delta t}$
B
$\frac{\Delta\left[\mathrm{Br}^{-}\right]}{\Delta t}=\frac{6}{5} \frac{\Delta\left[\mathrm{H}^{+}\right]}{\Delta t}$
C
$\frac{\Delta\left[\mathrm{Br}^{-}\right]}{\Delta t}=\frac{5}{6} \frac{\Delta\left[\mathrm{H}^{+}\right]}{\Delta t}$
D
$\frac{\Delta\left[\mathrm{Br}^{-}\right]}{\Delta t}=6 \frac{\Delta\left[\mathrm{H}^{+}\right]}{\Delta t}$
13
MCQ (Single Correct Answer)
Which of the following graphs represents exothermic reaction?
A
Only (I)
B
Only (II)
C
Only (III)
D
(I) and (III)
14
MCQ (Single Correct Answer)
Rate law for the reaction $\mathrm{A}+2 \mathrm{~B} \longrightarrow \mathrm{C}$ is found to be
$$\text { Rate }=k[A][B]$$
Concentration of reactant ' B ' is doubled, keeping the concentration of ' A ' constant, the value of rate constant will be ............... .
A
the same
B
doubled
C
quadrupled
D
halved
15
MCQ (Single Correct Answer)
Which of the following statements is incorrect about the collision theory of chemical reaction?
A
It considers reacting molecules or atoms to be hard spheres and ignores their structural features
B
Number of effective collisions determines the rate of reaction
C
Collision of atoms or molecules possessing sufficient threshold energy results into the product formation
D
Molecules should collide with sufficient threshold energy and proper orientation for the collision to be effective