3. Methyl acetate is hydrolyzed at 25 oC in acidic environment. Aliquots of equal volume are removed and titrated with NaOH solution. The hydrolysis reaction is irreversible. The results are Time/s 339 1242 2745 4546 infinite Volume of base/ mL 26.34 27.80 29.70 31.81 39.81 Write the reaction of hydrolysis of methyl acetate. (3 pts.) Neglect the reverse reaction. Find the order of the hydrolysis reaction and the value of the rate constant at this temperature. (12 pts.) Total 15 pts.

Solution :

Time (sec)       Volume of NaOH (mL)

339                           26.23

1242                         27.80

2745                        29.70

4546                         3.81

                              39.81

Now the example of the first order kinetics w.r.t volumetric analysis is :

Here,

= volume at time 0 = 0

Since the interval is not constant, we take the time interval as

= 1402.3333

≈  1402 seconds

  = 0.001643 x 0.52045

  = 0.00082

Therefore, the first order rate constant is k .

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

the answer is na (sodium)