In the reaction BrO^-₃ (aq) + 5 Br ^- (aq) + 6 H⁺ \(\longrightarrow\) 3 Br₂(I) + 3 H₂O (l), the rate of apperance of bromine (BHr₂) is related to the disapearance of bromide uions as follows :

1

(a)

\(\frac { d[{ Br }_{ 2 }] }{ dt } =-\frac { 5 }{ 3 } \frac { d[{ Br }^{ - }] }{ dt } \)

(b)

\(\frac { d[{ Br }_{ 2 }] }{ dt } =\frac { 5 }{ 3 } \frac { d[{ Br }^{ - }] }{ dt } \)

(c)

\(\frac { d[{ Br }_{ 2 }] }{ dt } =\frac {3 }{ 5} \frac { d[{ Br }^{ - }] }{ dt } \)

(d)

\(\frac { d[{ Br }_{ 2 }] }{ dt } =-\frac { 3 }{ 5 } \frac { d[{ Br }^{ - }] }{ dt } \)

 The rate of  the reaction 2 NO + CI₂ \(\rightarrow\) 2NOCI is given by the rate equation : rate = k [NO]₂ [CI₂]. The value  of the rate constant can be increased by

1

(a)

increasing the temperature

(b)

increasing the concentration of NO

(c)

increasing the concentration of CI₂

(d)

doing all of these

The unit of rate constant for a zero order reaction is

1

(a)

mol L^-1 s^-1

(b)

L mol^-1 s^-1

(c)

L²mol^-1 s^-1

(d)

s^-1

A first order reaction has a half-life period of 34.65 seconds. Its rate constant is 

1

(a)

2 \(\times 10\) ^-2 sec^-1

(b)

4 \(\times 10\) ^-4 sec^-1

(c)

20 sec^-1

(d)

2 \(\times 10\) ^-4 sec^-1

Rate constant of a reaction (k) is 175 litre² mol^-2 sec^-1. What is the order of reaction?

1

(a)

first

(b)

second

(c)

third

(d)

zero

Identify the reaction order from each of the following rate constants.
(i) k = 2.3 \(\times\) 10^-5 L mol ^-1 s^-1
(ii) k = 3 10^-4 \(\times\) s ^-1

1

(a)

Why does the rate of a reaction not remain constant throughout the reaction process?

1

(a)

It is because concentration of reactants goes on decreasing with time.

For the reaction Cl₂(g) + 2NO(g) \(\to\) 2NOCl(g) the rate law is expressed as rate = k[Cl₂][NO]² What is the overall order of this reaction?

1

(a)

The overall order of reaction is 3.

Express the rate of the following reaction in terms of disappearance of hydrogen in the reaction: 3H₂ (g) + N₂ (g) \(\to\) 2 NH₃ (g).

1

(a)

- \(1\over3\)\(d[H_{2}]\over 3 \ dt\) represents rate of reaction.

The rate of reaction X \(\to\) Y becomes 8 times when the concentration of the reactant X is doubled. Write the rate law of the reaction.

1

(a)

\(dx\over dt\) = k[X]³ as 2³ = 8     \(\therefore\) order is 3.

Is there any reaction for which reaction rate does not decrease with them?

1

(a)

Yes, zero order reaction.

Express the relation between the half-life period of a reactant and its initial concentration if the reaction involved is of second order.

1

(a)

\(t_{1/2}\) is inversely proportional to initial concentration in second order reaction

i.e. t_1/2 \(\propto \) \(1\over [R]_{0}\) where [R]₀ is initial concentration.

Express the relation between the half-life period of a reactant and its initial concentration for a reaction of n^th order.

1

(a)

\(t_{1/2} \propto {1\over [R]^{n-1}_{0}}\) where 'n' is order of reaction.

State a condition in which bimolecular reaction is kinetically first order reaction.

1

(a)

When one of the reactants is in excess, bimolecular reaction becomes kinetically first order.

For a reaction A + B \(\to\) Products, the rate law is Rate = k[A] [B]^3/2. Can the reaction be an elementary reaction?

1

(a)

No, it is not elementary reaction.  Had this be elementary reaction order with respect to 'B' should have been 1.

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

1

(a)

No, molecularity can never be equal to zero or in fraction.