In the following reaction sequence, major products X and Y are acyclic monomers. CH3I [ 3. Red P, Br2\ 4. NH3 (excess)] 1. KCN\ 2. H3O+, X [figure] 500 mol of X completely reacts with 500 mol of Y to give 1 mol of a single biodegradable acyclic copolymer Z as the only product. The amount of Z formed in grams is . Given: Atomic mass (in amu): H : 1, C : 12, N : 14, O : 16, Br : 80
Answer
85018 to 85138.02
Solution
[figure] KCN [figure] H3O+, [figure]
SN2 by CN- gives ethanenitrile; acid hydrolysis of –CN gives ethanoic acid.
[figure] Red P, Br2 [figure] NH3 (excess) [figure] (X)
HVZ reaction brominates the α-carbon; excess NH3 replaces Br by -NH2: X = glycine (75 g mol-1).
[figure] [ ]H3O+ [figure] (Y)
Hydrolysis opens the lactam (cyclic amide): Y = 6-aminohexanoic acid (131 g mol-1).
X + Y Z = nylon-2-nylon-6, [-NH-CH2-CO-NH-(CH2)5-CO-]n: one linear chain of 1000 monomer units joined by 999 amide bonds, each releasing one H2O.
Mass of Z =500 75+500 131-999 18=37500+65500-17982=85018 g
Answer: 85018