Chapter 12: Q12.3B CYL (page 662)

In a transesterification reaction, a triglyceride reacts with an alcohol to form an ester and glycerol. Many students learn about the reaction between methanol (\({\bf{C}}{{\bf{H}}_{\bf{3}}}{\bf{OH}}\)) and ethyl acetate (\({\bf{C}}{{\bf{H}}_{\bf{3}}}{\bf{C}}{{\bf{H}}_{\bf{2}}}{\bf{OCOC}}{{\bf{H}}_{\bf{3}}}\)) as a sample reaction before studying the chemical reactions that produce biodiesel:
\({\bf{C}}{{\bf{H}}_{\bf{3}}}{\bf{OH + C}}{{\bf{H}}_{\bf{3}}}{\bf{C}}{{\bf{H}}_{\bf{2}}}{\bf{OCOC}}{{\bf{H}}_{\bf{3}}}{\bf{ - - - C}}{{\bf{H}}_{\bf{3}}}{\bf{OCOC}}{{\bf{H}}_{\bf{3}}}{\bf{ + C}}{{\bf{H}}_{\bf{3}}}{\bf{C}}{{\bf{H}}_{\bf{2}}}{\bf{OH}}\).The rate law for the reaction between methanol and ethyl acetate is, under certain conditions, determined to be: rate =\(k\left( {{\bf{C}}{{\bf{H}}_{\bf{3}}}{\bf{OH }}} \right)\). What is the order of reaction with respect to methanol and ethyl acetate, and what is the overall order of reaction?

Short Answer

Expert verified

The orders with respect to each reactant order in \({\bf{C}}{{\bf{H}}_{\bf{3}}}{\bf{OH}}\)= 1; order in \({\bf{C}}{{\bf{H}}_{\bf{3}}}{\bf{C}}{{\bf{H}}_{\bf{2}}}{\bf{OCOC}}{{\bf{H}}_{\bf{3}}}\)= 0; and the overall order of the reaction overall order = 1.

Step by step solution

Rate of a Reaction

The rate of reaction may be defined as the speed of the reactant reacting to obtain a product in a particular reaction at a particular time. The concentration of the reactant and product are represented in terms of mole/L.

\({\bf{rate = k}}{\left( {\bf{A}} \right)^{\bf{m}}}{\left( {\bf{B}} \right)^{\bf{n}}}^{}\)

Explanation

\({\bf{rate = k}}{\left( {\bf{A}} \right)^{\bf{m}}}{\left( {\bf{B}} \right)^{\bf{n}}}^{}\)\(\)

Here m = 1 and n =0

rate =\(k\left( {{\bf{C}}{{\bf{H}}_{\bf{3}}}{\bf{OH }}} \right)\)

Therefore:

The orders with respect to each reactant order in \({\bf{C}}{{\bf{H}}_{\bf{3}}}{\bf{OH}}\) = 1; order in \({\bf{C}}{{\bf{H}}_{\bf{3}}}{\bf{C}}{{\bf{H}}_{\bf{2}}}{\bf{OCOC}}{{\bf{H}}_{\bf{3}}}\)= 0; and the overall order of the reaction overall order = 1.