341.

For the reaction A +2B → C, the reaction rate is doubled, if the concentration of A is doubled. The rate is increased by four times when concentrations of both A and B are increased by four times. The order of the reaction is

• 3

• 0

• 1

• 2

The increase in rate constant of a chemical reaction with increasing temperature is (are) due to the fact(s) that

• the number of collisions among the reactant molecules increases with increasing temperature

• the activation energy of the reaction decreases with increasing temperature

• the concentration of the reactant molecules increases with increasing temperature

• the number of reactant molecules acquiring the activation energy increases with increasing temperature

The rate of a certain reaction is given by, rate = k [H⁺]ⁿ. The rate increases 100 times when the pH changes from 3 to 1. The order (n) of the reaction is

• 2

• 0

• 1

• 1.5

Acid catalysed hydrolysis of ethyl acetate follows a pseudo-first order kinetics with respect to ester. If the reaction is carried out with large excess of ester, the order with respect to ester will be

• 1.5

• 0

• 0.5

• 1

The half-life for decay of ¹⁴C by β-emission is 5730 yr. The fraction of ¹⁴C decays, in a sample that is 22920 yr old, would be

• $\frac{1}{8}$

• $\frac{1}{16}$

• $\frac{7}{8}$

• $\frac{15}{16}$

A piece of wood from an archaeological sample has 5.0 counts min^-1 per gram of C-14, while a fresh sample of wood has a count of 15.0 min^-1g^-1. If half-life of C-14 is 5770 yr, the age of the archaeological sample is

• 8,500 yr

• 9,200 yr

• 10,000 yr

• 11,000 yr

Consider the following reaction for 2NO₂(g) + F₂(g) → 2NO₂Fg). The expression for the rate of reaction in terms of the rate of change of partial pressure of reactant and product is/are

• rate = $-\frac{1}{2}\left[\frac{\mathrm{dp}\left({\mathrm{NO}}_2\right)}{\mathrm{dt}}\right]$

• rate = $\frac{1}{2}\left[\frac{\mathrm{dp}\left({\mathrm{NO}}_2\right)}{\mathrm{dt}}\right]$

• rate = $-\frac{1}{2}\left[\frac{\mathrm{dp}\left({\mathrm{NO}}_2\mathrm{F}\right)}{\mathrm{dt}}\right]$

• rate = $\frac{1}{2}\left[\frac{\mathrm{dp}\left({\mathrm{NO}}_2\mathrm{F}\right)}{\mathrm{dt}}\right]$

The bacterial growth follows the rate law, $\frac{\mathrm{dN}}{\mathrm{dt}}$ = kN where k is a constant and 'N' is the dt number of bacteria cell at any time. If the population of bacteria (number of cell) is doubled in 5 min find the time in which the population will be eight times of the initial one?

$\mathrm{For} \mathrm{the} \mathrm{reaction}, 2{\mathrm{NO}}_2+ {\mathrm{F}}_2\to 2{\mathrm{NO}}_2\mathrm{F},$ following mechanism has been provided. 

$$\begin{gathered} {\mathrm{NO}}_2+ {\mathrm{F}}_2 \stackrel{\mathrm{slow}}{\to } {\mathrm{NO}}_2\mathrm{F} + \mathrm{F} \\ {\mathrm{NO}}_2+ {\mathrm{F}}_2 \stackrel{\mathrm{Fast}}{\to } {\mathrm{NO}}_2\mathrm{F} \end{gathered}$$

Thus, rate expression of the above reaction can be written as

• r =k [NO₂]²[F₂]

• r= k [NO₂] [F₂]

• r= k [NO₂]

• r= k [F₂]

For a reaction,  ${\mathrm{I}}^{-}+ {\mathrm{OCl}}^{-} \to {\mathrm{IO}}^{-} + \mathrm{Cl}$ an aqueous medium, the rate of reaction is given by:

                     $\frac{\mathrm{d}\left[{\mathrm{IO}}^{-}\right]}{\mathrm{dt}}= \mathrm{k} \frac{\left[{\mathrm{I}}^{-}\right] \left[{\mathrm{OCl}}^{-}\right]}{\left[\mathrm{OH}\right]}$

The overall order of reaction is

• -1

• 0

• 1

• 2