Question

The hydrolysis of ethyl acetate is a reaction of:
$C{{H}_{3}}COO{{C}_{2}}{{H}_{5}}+{{H}_{2}}O\xrightarrow{{{H}^{+}}}C{{H}_{3}}COOH+{{C}_{2}}{{H}_{5}}OH$
a.) Zero order
b.) First order
c.) Second order
d.) Third order

Answer 1

Hint: The order of reaction is defined as the addition of the powers of the concentration of reactants written in rate law expression.

Complete answer:
Order of any reaction is directly proportional to the mole fraction of reactants.
Reaction of hydrolysis of ethyl acetate is:
$C{{H}_{3}}COO{{C}_{2}}{{H}_{5}}+{{H}_{2}}O\xrightarrow{{{H}^{+}}}C{{H}_{3}}COOH+{{C}_{2}}{{H}_{5}}OH$
Reactants are ethyl acetate and water
Therefore, their rate is equal to the concentration of ethyl acetate and water raised to their respective moles.
 $rate={{[C{{H}_{3}}COO{{C}_{2}}{{H}_{5}}]}^{x}}{{[{{H}_{2}}O]}^{y}}$
Order of the reaction is equal to the sum of their powers that is the sum of x and y.
\[Order\text{ }of\text{ }the\text{ }reaction=x+y\]
Where, x is the number of moles of ethyl acetate and y is the number of moles of water.
Number of moles of ethyl acetate is1 i.e. y=1
Number of moles of water is 1 i.e. x=1
$rate={{[C{{H}_{3}}COO{{C}_{2}}{{H}_{5}}]}^{1}}{{[{{H}_{2}}O]}^{1}}$
Sum of x and y comes out to be 2, so the order is equal to two.
Therefore, it is the second order reaction which is option C.

Note: The order of reaction is defined as the addition of the powers of the concentration of reactants written in rate law expression. Rate of reaction can be 0,1,2,3,4 and even a fraction.
If the reactant in a product is A and B
Then the rate law expression is written as:
 $rate=k{{[A]}^{x}}{{[B]}^{y}}$
Where k is the rate constant and x represents the number of moles of reactant A and y represents the number of moles of B.
Order of reaction would be equal to the sum of x and y.
$order=x+y$
Concentrations of reactants are not considered in zero order reaction as its order is zero so it is concentration independent.