Question

Decide with a brief explanation of the following statements about reaction rates and catalysis are true:

a) A reaction is the first order of chloride ion concentration. Doubling the chloride ion concentration then doubles the rate of the reaction.

b) A unimolecular elemental reaction is always total of the first order.

c) The speed law describes how the reaction rate depends on the temperature.

d) Catalysis means that the equilibrium constant becomes larger.

e) In the Haber-Bosch reaction, a heterogeneous catalyst is used to accelerate the equilibrium setting

Answer 1

a) True

suppose rate law of a first order reaction having chloride ion as reactant, rate = k[Cl^-]

if the concentration of the Cl^- is doubled, rate = k[2Cl^-]

= rate =2 k[Cl^-], the rate is doubled.

b)  A unimolecular elemental reaction is always total of the first order. - True

Here only one molecule makes up the transition state

( Butnon elementary unimolecular reactions need not be first order)

c) False

The rate law describes how rate of reaction depends on concentration of the reactants, bot not on temperature.

d) False - catalyst helps reaction reach faster . But equiliibrium constant is changed by the changing temperature. Equilibrium constant value depends on temperature and not on catalysis. catalysis helps attainment of equilibrium faster.

e) True ---  In the Haber-Bosch reaction, a heterogeneous catalyst is used to accelerate the equilibrium setting . In this manufacture of ammonia iron powder is used to accelerate the equilibrium. Reactants -- nitrogen and hydrogen are in gaseous state and iron is in solid state.