Question

Fisher esterification of m-nitrobenzoic acid with methanol gives the desired product.

a) Write a balanced chemical equation for this reaction.

b) If you started with 3.0 g of m-nitrobenzoic acid, 8.0 mL of methanol, and 5.0 mL of water, then you are able to isolate 2.8 g of the desired product. Calculate the value of the equilibrium constant (Keq) using an ICE table?

c) Calculate the percent yield for the above reaction.

d) How many peaks for the different types of protons would you observe in the proton NMR spectrum of the product obtained in the above reaction?

Answer 1

(a) Соосна COOH + CH OH cat H2S04 heat + H2O NOZ (b) Keq = for of M-NO, CHE CO_ch37[H20] [m- NO, CH5COOH] [CH,OH] Since, the volume of the reaction mixture is the same each components, we can use moles instead molarities Mole of [m-NO, GH3COOH); 3gm 167.129m/moh Mole of [CHzor]; (07 8ml) 32.042 g/mol 1: Density of methanol = 0.7919 0.018 moh 0.791 g x 8ml 0.197 moh mi mi Mole of [H₂o] ( 1.2 19 x 5ml) 0.278 mol mi 18.015 g/mol Male of [m.N10, çu, co, che], 2.89m 0.015 mol f 181.15 g/mol

{m-NO,CH3 0,44,]+[420] 0 0-279mol + X +X (mNO, GHz C004] + [C4,04] intah 0.018 moh 0.197mob at t=0 change -X -X at t-t' 0.018-X 0.197-X equilibrium As mole of (m.NO, CHs Co,CH] Hence, + X 0.2787 X 0.015 mol = X at tot' equilibrium 0.018-0.015 0.197 -0.015 0.015 0.278+0.015 0.293 0.003 = 0.182 8.049 So, Keq = [0.015][0.243] [0.003] (0.182] (c) % Yield = [moles methylrobenzoate obtained] x 100 (initial moles Nobenzoic acid] % Yield = 83.334% X 100 0.015 0.018 d) Hc HL = Hd There are 5 different type of protons, Ha Singlet Hal Iriplet Ho Singht He doublet He doublet He Ha NO 2