Chemistry, 21.07.2019 12:10 jetblackcap

Write a condensed structural formula for the repeat unit of the kevlar molecule

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Answer from: moningersavannah

Explanation:

Kevlar is a fiber which is used in making of bullet proof vests and armors. It is a co-polymer which is formed by condensing two organic molecules 1,4-phenylene-diamine and terephthaloyl chloride.

$NH_2C_6H_4NH_2+Cl-(CO)-C_6H_4-(CO)-Cl\xrightarrow[-2HCl]{ }$

NH_2-C_6H_4-NH-CO-C_6H_4-COOH

For Structure refer to image attached.

Write a condensed structural formula for the repeat unit of the kevlar molecule

Answer from: ariellllllllllllllll

The condensed formula for Kevlar is attached in the image.

Further explanation:

Polymerization is a process through which monomer molecules undergo addition or condensation reaction to form a three-dimensional network structure called polymers. They are also called as macromolecules.

Monomers are defined as low molecular weight compounds that undergo reaction to form high molecular weight compounds called polymers.

Types of polymerization:

Addition polymerization is also known as chain-growth polymerization. It mainly occurs by the reaction in which a carbon-carbon double bond adds to a carbon-carbon double bond. There is no loss of small molecules in it.

Condensation reaction is a reaction where a larger molecule is formed by a reaction between two reactants by loss of small neutral molecules like ${{\text{H}}_{\text{2}}}{\text{O}},{\text{N}}{{\text{H}}_3},{\text{HCl}}$ .

Kevlar is copolymer formed by condensation reaction between 1,4-phenylene-diamine and terephthaloyl chloride by loss of HCl molecule. It is heat resistant and strong synthetic fiber which is used in the making of bulletproof vests and armors.

The copolymerization of Kevlar occurs as follows:

${{\text{H}}_{\text{2}}}{\text{N}}{{\text{C}}_{\text{6}}}{{\text{H}}_{\text{4}}}{\text{N}}{{\text{H}}_{\text{2}}} + {\text{Cl}} - \left( {{\text{CO}}} \right) - {{\text{C}}_{\text{6}}}{{\text{H}}_{\text{4}}} - \left( {{\text{CO}}} \right) - {\text{Cl}}\; \to \;{\text{N}}{{\text{H}}_{\text{2}}}{{\text{C}}_{\text{6}}}{{\text{H}}_{\text{4}}} - {\text{NH}} - {\text{CO}} - {{\text{C}}_{\text{6}}}{{\text{H}}_{\text{4}}}{\text{COOH}}\;{\text{ + 2HCl}}$

Learn more:

1. To draw a Lewis structure when the condensed formula is given:

2. Write the condensed electronic configuration for monoatomic ion:

Answer details:

Grade: Senior Secondary School

Subject: Chemistry

Chapter: Polymerization

Keywords: Kevlar, condensation, fiber, polymerization, addition, terephthaloyl chloride and phenylenediamine.

Answer from: Quest

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

Answer from: Quest

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