Chlorine dioxide, ClO2, is a reddish yellow gas that is soluble in water. Its reaction in basic solution is: ClO2 + OH- → ClO3- + ClO2- + H2O
To obtain the rate law for this reaction, the following experiments were run, and for each, the initial rate of reaction of ClO2 was determined.
Initial Conc. (mol dm-3) Initial rate (mol dm-3min-1)
ClO2 OH-
Expt. 1 0.06 0.03 0.0248
Expt. 2 0.02 0.03 0.0276
Expt. 3 0.02 0.09 0.00828
a.
i. Calculate the change in oxidation state of the reducing and oxidizing redox couple
ii. Balance the redox reaction
iii. From the balanced redox reaction, if the rate of formation of ClO3- is 0.5moldm-3min-1, what is the rate of disappearance of OH- .
b. Deduce the rate law and rate constant of the reaction from the given experimental data (Hint: calculate the change in concentration of the reactants to at least three decimal places).
c. Based on your result in b. above, If the initial concentration of the hydroxide ion is 0.5moldm-3
i. What will be its concentration after four half-lives?
ii. What fraction of this concentration will have decomposed after three half-lives?
d. Aniline hydrochloride (C6H5NH3 +Cl-) is a salt formed by the reaction of aniline with hydrochloric acid.
i. Briefly explain with an equation whether the aqueous salt solution will be acidic or basic?
ii. Write the equilibrium expression
iii. What is the pOH of an aqueous solution of 0.5M aniline hydrochloride? The chloride ion in the
salt has no acid-base property. Kb for the salt = 4.0 x 10- 10