Collision Theory

Q. Explain briefly the collision theory of bimolecular reactions.

Q.

Write any two criteria for effective collision.

Q.

In the equation $\mathrm{k}={\mathrm{Z}}_{\mathrm{AB}}{\mathrm{e}}^{\frac{-\mathrm{Ea}}{\mathrm{RT}}}$ what does ${\mathrm{e}}^{\frac{-\mathrm{Ea}}{\mathrm{RT}}}$represent?

Q.

In the equation, rate$={\mathrm{Z}}_{\mathrm{AB}}{\mathrm{e}}^{\frac{-\mathrm{Ea}}{\mathrm{RT}}}$what does ${\mathrm{Z}}_{\mathrm{AB}}$ means?

Q.

State the postulates of collision theory. Explain the effects of temperature, concentration, and catalyst on the rate of reaction.

Q. Chemical reactions with very high $E_a$ values are generally:

1. Very fast
2. Very slow
3. Moderately fast
4. Spontaneous

Q.

Explain the effect of a catalyst on the rate of reaction on the basis of collision theory.

Q. Choose the statement(s) which are correct according to the collision theory.

1. There must be collisions between the reactant molecules for a reaction to occur.
2. All collisions between reactant molecules should form product.
3. Decrease in the number of the molecules increases number of effective collision.
4. Increase in the energy of the molecules increases number of effective collision.

Q. Match the following

$\begin{array}{cccc}a)& a& \left(i\right)& Activationenergyofforwardreaction\\ b)& b& \left(ii\right)& Changeinenthalpy\\ c)& c& \left(iii\right)& Activationenergyofbackwardreaction\\ d)& d& \left(iv\right)& PotentialEnergyofReactants\\ e)& e& \left(v\right)& PotentialenergyofProducts\end{array}$

1. a – (i) b – (iv) c – (v) d – (iii) e – (ii)
2. a – (v) b – (iv) c – (i) d – (iii) e – (ii)
3. a – (iv) b – (i) c – (v) d – (iii) e – (ii)
4. a – (iv) b – (i) c – (v) d – (ii) e – (iii)

Q. Higher order (>3) reactions are rare due to

1. increase in entropy and activation energy as more molecules are involved
2. shifting of equilibrium towards reactants due to elastic collisions
3. low probability of simultaneous collision of all the reacting species
4. loss of active species on collision

Q.

For a chemical reaction to occur

1. the reacting molecules must collide with each other

2. reacting molecules should have sufficient energy at the time of the collision

3. reacting molecules must be properly oriented

4. all of the above

Q. Reaction A + B $\to$ C + D + 38 kcal, has activation energy 20 kcal, Activation energy for reaction C + D $\to$ A + B is

1. 20 kcal
2. 18 kcal
3. -20 kcal
4. 58 kcal