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The repeating structural unit of most simple polymers not only reflects the monomer(s) from which the polymers are constructed, but also provides a concise means for drawing structures to represent these macromolecules. The repeating structural unit of most simple polymers not only reflects the monomer(s) from which the polymers are constructed, but also provides a concise means for drawing structures to represent these macromolecules. 14.4 (a) Compute the repeat unit molecular weight of polystyrene. The incredible insulating capabilities of polystyrene can maintain the temperature hot or cold. The examples of homopolymer are: polystyrene, polyethylene, polyvinyl chloride. The difference C p – C v was calculated at 273°K. In this diagram the little "n" means that this group of atoms is repeated over and over to make the large polystyrene molecule … It is a flexible, easily moulded, waterproof, Answer. (b) The polymer shown above contains methyl groups (CH 3). The repeat unit is highlighted in blue. Polystyrene can be naturally transparent, but can be co… What is the value of n if the molecular mass of a single polymer chain is 1.5782 x 106 amu? Teflon: Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene. Thus, made into the repeating unit of a large, polymeric (multiple-unit) molecule, ethylene has the following chemical structure:. The difference between polystyrene and polyethylene is that each repeat unit in styrene has a big pendant group instead of one of the H's. For example, polystyrene chains may be grafted onto polybutadiene, a synthetic rubber which retains one reactive C=C double bond per repeat unit. Trending questions. Introduction. Ethylene molecules are essentially composed of two methylene units (CH 2) linked together by a double bond between the carbon atoms—a structure represented by the formula CH 2 =CH 2. The growing chains can add across the double bonds of rubber molecules forming polystyrene branches. 5 answers. If asked to draw one repeating unit, don’t add the n on to your diagram, because n represents a large number C C H CH3 H H Poly(e thene) -polythene Poly(e thene): is used to make plastics bags, buckets, bottles. Trending questions. Question: Polystyrene, One Of The Most Widely Used Plastics In The World, Has The Formula Shown. Just enter your phone number below. Join. 3. constitutes the repeating units. Here's an example: We notice that the repeating unit is linked to the rest of the chain by amide functional groups, and that the repeating unit contains an amide group. We connect students with top tutors from the IITs and BITS - instantly, anytime, anywhere. There are usually between 104 to 106 repeating units in a chain C C C C C C CH3 H H H CH3 H H H CH3 H H H be able to recognise the repeating unit in a poly(a lkene) Poly(a lkenes) like alkanes are unreactive due to the strong C-C and C-H bonds Monomer Polymer n ... Poly(phe nylethene) also known as polystyrene C C H H H phenylethene The phenyl group is -C6H5 See chapter 6.9 on … It is a rather poor barrier to oxygen and water vapour and has a relatively low melting point. Compute the degree of polymerization for a polystyrene (PS) polymer with a number-average molecular weight of 260150 g/mol. The condensation involves loss of water, as an H is lost from each HO- group in the glycol, and an OH from each HOOC- group in the acid. 9. polystyrene and polypropylene are some examples of plastic in industry. A single molecule of polystryene has the repeating unit - [CH2CH (C6H5)]n-, where n is the number of repeating units. 1. constitutes the repeating units. The repeat unit is highlighted in blue. Transcribed Image Text 2 pts Question 13 The repeat unit of polystyrene, which has 8 carbon atoms, and 8 hydrogen atoms. Trending questions. When drawing one, you need to: Answer with step by step detailed solutions to question from Arihant's BITSAT Prep Guide, Polymers- "Repeating unit of polystyrene is" plus 6299 more questions from Chemistry. All you need to do to show any repeat unit is break the double bond, show where new bonds will form if the molecule reacts with another monomer and then put a bracket around that part. Polymers are large molecules that have the same structural unit repeating over and over. Given that the atomic weight of carbon and hydrogen is 12.01 g/mol and 1.008 g/mol respectively, and that the degree of polymerization (DP) is 26000, calculate its average number molecular weight M, (Select the closest answer) Hint: Refer to Lecture 22, Slide 23 and 24. The incredible insulating capabilities ... composed of a large number of repeating units. In Reaction 5, since the double bond is in a different position (the C1 position), the polymer formed will have as its repeating unit a carbon atom with 2 hydrogen atoms attached, and a carbon atom with one hydrogen attached and a … We serve Class 8th - 12th students preparing for CBSE, ICSE and State boards as well as all entrance exams such as IIT JEE Main & Advanced, BITSAT, NEET, VITEEE, MU OET, SRMEEE, AIPMT and all State entrance exams. The examples of homopolymer are: polystyrene, polyethylene, polyvinyl chloride. As such, polystyrene is most likely to dissolve in solvents that are hydrocarbon-like. Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. 2 pts Question 13 The repeat unit of polystyrene, which has 8 carbon atoms, and 8 hydrogen atoms. Join Yahoo Answers and get 100 points today. Ex: calculate the degree of polymerization of a sample of polyethylene [ (CH2-CH2)n], which has a molecular weight of 150,000 g/mol. Polystyrene is a hydrocarbon polymer that is made of repeating units of styrene. (a) Draw the structure of the repeating unit in the superglue polymer. M is the molecular weight of the polymer, DP is the degree of polymerization and the M 0 is the formula weight of the repeating unit. Polypropylene and polystyrene are two types of commonly used polymers in the manufacture of plastic laboratory consumables. Compute the molecular weight of a singe (1), polystyrene (PS) repeat unit. polystyrene and polypropylene are some examples of plastic in industry. What is the number-average molecular weight of a PC polymer that features a degree of polymerization of 2175 ? Extruded polystyrene (XPS) is commonly used in architectural models. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. (a) Compute the repeat unit molecular weight of polystyrene. (ii) Compare and contrast the polymer formed in Reaction 5 to the polymer formed in Reaction 3. Polystyrene exists in two main forms: as a solid or as a foam. HashLearn is the #1 platform to get online coaching for competitive exams. (Gowariker et al.,2009) Polystyrene is playing an important role in this modern life nowadays because of its efficiency, cost-effectiveness and lightweight. HashLearn is India's first on-demand tutoring app. Polystyrene is made from the monomer styrene which is a liquid petrochemical. A polymer is composed of many simple molecules that are repeating structural units called monomers. Other than monodisperse polymers, there is normally a molar mass distribution caused by chains of different length. Ex: calculate the degree of polymerization of a sample of polyethylene [ (CH 2-CH 2) n], which has a molecular weight of 150,000 g/mol. 104.4 g/mol. Ask question + 100. Polystyrene MW is shown to have no significant impact on the film thickness dependence of Tg − Tg,bulk. A single molecule of polystryene has the repeating unit -[CH 2 CH(C 6 H 5)] n-, where n is the number of repeating units. Polymer is a combination of small … 1. A copolymer consists of two or more different monomers as repeating units, such as the diblock copolymer: and the random or static copolymer: An example is the polystyrene-poly(methyl methacrylate) copolymer. Polystyrene. Polystyrene has a chain where the substituent R is a phenyl group (C6H5), corresponding to a benzene ring minus one hydrogen: -[CH2-CH(C6H5)]n-, so the repeat unit is -[CH2-CH(C6H5)]-. M is the molecular weight of the polymer, DP is the degree of polymerization and the M 0 is the formula weight of the repeating unit. 2. For example, in polyethylene terephthalate (PET or "polyester"), the repeat unit is -CO-C6H4-CO-O-CH2-CH2-O-. [2], An atom or group of atoms (with pendant atoms or groups, if any) comprising a part of the essential structure of a macromolecule, an oligomer molecule, a block or a chain. The numbers preceding the poly prefix designate the first and last carbon atoms of the backbone repeating unit. In fact, polymer molecules are often hundreds or thousands of monomer units long. I'm trying to calculate the unit molecular weight of polystyrene. The correct answer is 8C +8H. One repeat unit therefore has a molar mass of M(C 3H 6) = 42:08gmol 1. The SPME fibre hosts in a Valco-tee unit sealed by a vespel ferrule. Get answers by asking now. ... (polyvinyl chloride), styrene (phenylethylene, polystyrene), methyl methacrylate (Plexiglas), and acrylonitrile (cyanoethylene, acrylic fibers). Still have questions? A polymer may be a chain of thousands of monomers, and so it is impossible to draw the entire polymer. It is an inexpensive resin per unit weight. Hydrogen is an explosive gas, oxygen supports combustion, why, when adding 2 hydrogen atoms to 1 oxygen atom, is the result an inert liquid? Join Yahoo Answers and get 100 points today. inter molecular forces (lower to higher). The squiggly lines indicate that the polymer molecule extends further at both the left and right ends. Get answers by asking now. Chemistry; Thread starter AndrewDe; Start date Sep 27, 2017; Sep 27, 2017 #1 AndrewDe. Polymers consist of many repeating monomer units in long chains, ... many monomers called styrene are polymerized into a long chain polymer called polystyrene. A copolymer consists of two or more different monomers as repeating units, such as the diblock copolymer: and the random or static copolymer: An example is the polystyrene-poly(methyl methacrylate) copolymer. The numbers preceding the poly prefix designate the first and last carbon atoms of the backbone repeating unit. The brackets contain the repeating unit. A polymer can be a 3-dimensional (3D) network Imagine of a repeating unit joined together left and right, back and front, up and down or it is a 2-dimensional (2D) network Imagine of the repeating units linked together right, left, down, and up in a sheet or a 1-dimensional (1D) network Imagine of a repeating unit … 1,2-poly(1,3-butadiene) has a vinyl-type structure, where the substituent group (ethene) contains an unsaturated … Repeating units can also be made from two monomers. Thus, m = 8(AC) + 8(AH) = … To calculate the weight, I keep counting 8C & 7H. The average number of mer-units in a chain. Still have questions? The two structural units in the polymer are then considered to be -CO-C6H4-CO- and -O-CH2-CH2-O-. The aqueous sample is pumped by a HPLC pump from the sample vial through the extraction cell and back to the reservoir (closed loop). In many condensation polymers the repeat unit contains two structural units related to the comonomers which have been polymerized. From Table 14.5, the acrylonitrile repeat unit contains 3 Carbon atoms, 1 Nitrogen atom and 3 Hydrogen atoms. 0 0. Answer to: The repeat unit in a polystyrene coffee cup has the formula C6H5CHCH2. (b) A simplified representation of polyvinyl acetate. The word polymer derives its meaning from this, which means "many mers." Solution for The repeat unit in polystyrene coffee cup has C6H5CHCH2. 2501.0 . The molecular mass of the chain is just the product nMR. This chain contains units that repeat themselves, known as repeating units. A single polymer molecule may consist of hundreds to a million monomers and may have a linear, branched, or network structure. Polystyrene is made from the monomer styrene which is a liquid petrochemical. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. units. The simplest way to understand the term polymer is a beneficial chemical made of many repeating units. Here's a molecule of polystyrene. (2014) (c) (i) Draw TWO repeating units of the polymer formed in Reaction 5. Ethanol and methanol are not very hydrocarbon-like and are not good solvents for polystyrene. polystyrene, from Table 5.3, each repeat unit has eight carbons and eight hydrogens. Polymer molecules are very large compared with most other molecules, so the idea of a repeat unit is used when drawing a displayed formula. Hydrogen is an explosive gas, oxygen supports combustion, why, when adding 2 hydrogen atoms to 1 oxygen atom, is the result an inert liquid? The number of classically vibrating units per repeating unit of polystyrene was found to be 6.57. (Gowariker et al.,2009) Polystyrene is playing an important role in this modern life nowadays because of its efficiency, cost-effectiveness and lightweight. Thus, the molecular weight of the acrylonitrile repeat unit is: The repeating units are called monomers. The aqueous sample is pumped by a HPLC pump from the sample vial through the extraction cell and … For polystyrene, from Table 14.3, each repeat unit has eight carbons and eight hydrogens. C) + 8(A. 0 0. 2. H Select Rings Draw More Erase H H N H. This problem has been solved! Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. See the answer. The two repeat units in this co-polymer are acrylonitrile and butadiene. The polymer is formed by the condensation reaction of the two monomers terephthalic acid (HOOC-C6H4-COOH) and ethylene glycol (HO-CH2-CH2-OH), or their chemical derivatives. Draw The Monomer, Given That This Polymer Forms By Addition Polymerization. In copolymers there are two or more types of repeat unit, which may be arranged in alternation, or at random, or in other more complex patterns. Given that the repeating unit in polystyrene is 104 and that the distance between the carbon- carbon bonds in the main chain is 1.54 A calculate the following: The mean-square end-to-end distance for a polystyrene molecule with the molecular weight 10° by assuming that the molecule behaves like a freely rotating, freely joined volumeless chain. Polystyrene is a synthetic aromatic polymer made from the monomer styrene. d) Polypropylene has a repeat unit of (C 3H 6). A commercially important ABA-triblock copolymer is polystyrene-block-polybutadiene-block-polystyrene or SBS, a ... ,3-butadiene) (C and D). Show transcribed image text . and found to be 2.0 cal./mole°. A collection of products made from polystyrene: a cup, a guitar case, polystyrene carvings, and floating pool noodles. 5 answers. (a) Compute the repeat unit molecular weight of polystyrene. Discover (and save!) You can see it in this 3-D model on the right or in the diagram below. We can deduce the structrure of the monomers by imagining the compounds which might be used to make the amide group. HDPE is composed of macromolecules in which n ranges from 10,000 to … Rather, the structure of a polymer can be condensed and represented as shown in the figure below. The polybutadiene is dissolved in styrene, which is then subjected to free-radical polymerization. Repeating units Polymer molecules are very large compared with most other molecules , so the idea of a repeat unit is used when drawing a displayed formula. For polystyrene, from Table 14.3, each repeat unit has eight carbons and eight hydrogens. The molecular weight of a repeating unit, Mo= (12 x 2 + 1 x 4) g/ mol = 28 g/mol Repeating Unit Of Polystyrene. Edit: thread moved from non HW forum. The SPME fibre hosts in a Valco-tee unit sealed by a vespel ferrule. In this case the repeat unit has the same atoms as the monomer vinyl chloride CH2=CHCl. "Mer" originates from the Greek word "meros," which means a part. A commercially important ABA-triblock copolymer is polystyrene-block-polybutadiene-block-polystyrene or SBS, a thermoplastic elastomer (see Section 9.2.3). Physical Properties of Polymers Handbook, James E. Mark, 2007, p.445-452 is a good refer-ence. General-purpose polystyrene is clear, hard, and rather brittle. how big … A single molecule of polystryene has the repeating unit -[CH2CH(C6H5)]n-, where n is the number of repeating units. A polystyrene-based resin foam body according to claim 8, wherein said polymer is selected from the group consisting of a homopolymer comprised of as a repeating unit acrylic acid, methacrylic acid or a derivative thereof; a copolymer comprised of as repeating unit acrylic acid, methacrylic acid or a derivative thereof; a copolymer comprised of as repeating unit vinyl alkylate; and a copolymer … [3] Trending questions. Answer with step by step detailed solutions to question from Arihant's BITSAT Prep Guide, Polymers- "Repeating unit of polystyrene is" plus 6299 more questions from Chemistry. Polystyrene can be solid or foamed. Attend recorded … your own Pins on Pinterest (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. B) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. What is the degree of polymerization?… Polystyrene is one of the most widely used plastics, the scale of its production being several million tonnes per year. Thus, the molecular weight of the styrene repeat unit is: m s = 8(A C) + 8(A H) = 8(12.01 g/mol) + 8(1.008 g/mol) = 104.14 g/mol Let f b be the chain fraction of butadiene repeat units. acid polyamide 6 (nylon 6) In the last example, where the synthesis reaction requires the alternate combination of two different monomers, the repeating unit is formed by two … In your answer you should explain why the polymers formed in these two reactions are different. Under the influence of polymerization catalysts, the double bond can be broken and the resultant extra single bond used to link to a carbon atom in another ethylene molecule. (a) (i) Draw THREE repeating units of the polymer formed . If the molar mass of the polymer is 3.5x10^5. Repeating units can also be made from two monomers. Questions of this type are frequently asked in competitive entrance exams like Engineering Entrance Exams and are especially useful. constitutes the repeating units. 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