Question

Rates of Chemical Reactions: The Iodination Of Acetone

[CH_​3COCH​​₃]=4.075 [I_​2]=0.007962 [HCl]=1.051

Absorbance of dilute iodine solution at frequency 500nm = 0.506

Teperature of dilute iodine solution = 19.6 degrees

System 1 average slope = -.0015945

System 2 average slope = -0.0032355

System 3 average slope = -0.0037095

System 4 average slope = -0.00165

1. Using the equation A=X[I_​2​], calculate X

2. Calculate the initial rates of reactions for the four systems (rate is positive)

3. Calculate the initial concentrations of acetone, I₂, and H⁺ ion in each of the systems studied.

4. Calculate m and n and p using the equation rate = k[CH₃COCH₃​]^m[I₂]ⁿ[H⁺]^​p

Answer 1

Theory: Iodination Of Acetone:

CH3COCH3(aq) +I2(aq) +H⁺⁽aq) ----->CH3COCH2I(aq) +I^-(aq) +H⁺(aq)

Rate law,

Rate=k[CH₃COCH₃​]^m[I₂]ⁿ[H⁺]^​p where K=rate constant,

m,n,p are the respective order of rxn for acetone,I2 and H+

if all the other reactants are kept constant,other than I2,then

1) rate=A[I2]^n ,A=k[CH₃COCH₃​]^m[H⁺]^​p

log rate=log A +n log [I2] ,n=slope of the graph (graph of log rate Vs log [I2])

2) initial rate=[I2]/t [I2 is completely used up so chnge of [I2]=[I2]=[I2]initial]

3)[acetone]initial=(Concentration of stock acetone)*Volume of stock/total volume

[I2]initial=(Concentration of stock I2 aq)*Volume of stock I2 aq/total volume

[H+]initial=(Concentration of stock [H+] aq)*Volume of stock [H+] aq/total volume

4) calculate initial rate= [I2]/t for all the four systems

plug in the value in the equation,

initial rate= k[CH₃COCH₃​]^m[I₂]ⁿ[H⁺]^​p

^{you get 4 equations and four unknowns k,m,n,p.Solve the equation to get the values for the unknowns k,m,n,p}