The incredible insulating capabilities of polystyrene can maintain the temperature hot or cold. 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. Nov 4, 2015 - This Pin was discovered by Nikki Parsons. Polymers consist of many repeating monomer units in long chains, ... many monomers called styrene are polymerized into a long chain polymer called polystyrene. 0 0. Source(s): https://owly.im/a8y7V. The repeat unit is highlighted in blue. Citing Literature 1= 5:9, whereas for polystyrene C 1= 9:5. If the molar mass of the polymer is 3.0 × 105 g/mol, what is the degree of In this diagram the little "n" means that this group of atoms is repeated over and over to make the large polystyrene molecule … Constitutional repeating unit (CRU), A repeat unit is sometimes called a mer or mer unit. Transcribed Image Text 2 pts Question 13 The repeat unit of polystyrene, which has 8 carbon atoms, and 8 hydrogen atoms. Questions of this type are frequently asked in competitive entrance exams like Engineering Entrance Exams and are especially useful. 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. The molecular mass of the repeat unit, MR, is simply the sum of the atomic masses of the atoms within the repeat unit. Repeating Unit Of Polystyrene. Here's a molecule of polystyrene. Polystyrene exists in two main forms: as a solid or as a foam. 2. Introduction. n is usually between 2,000 and 100,000 units. Repeating Unit Of Polystyrene. Join Yahoo Answers and get 100 points today. It is a flexible, easily moulded, waterproof, For polystyrene, from Table 14.3, each repeat unit has eight carbons and eight hydrogens. This chain contains units that repeat themselves, known as repeating units. (Gowariker et al.,2009) Polystyrene is playing an important role in this modern life nowadays because of its efficiency, cost-effectiveness and lightweight. Trending questions. What is the number-average molecular weight of a PC polymer that features a degree of polymerization of 2175 ? 5 answers. Thus, made into the repeating unit of a large, polymeric (multiple-unit) molecule, ethylene has the following chemical structure:. D) 2.047 10 4 units. units. Polystyrene polymer beads purchased from Polyscience were washed by a series of centrifugation steps with distilled deionized water (Fig. Isotactic polystyrene is said to be highly crystalline. C) 3.031 10 4 units. Thus, m = 8(AC) + 8(AH) = (8)(12.01 g/mol) + (8)(1.008 g/mol) = 104.14 g/mol (b) We are now asked to compute the number-average molecular weight. On the basis of structure of polymers, they can be, The correct classification of polymers based on, Synthetic polymer prepared by using caprolactam is, Relation between number of av er age molecular mass, The structural formula of monomer of poly methyl, $ Nylon $-66 B=$ Buna $-S,C=$ olyethene, Arrange these in the increasing order of their. Bakelite is obtained from phenol by re acting it with. More complex repeat units can occur in vinyl polymers -[CH2-CHR]n-, if one hydrogen in the ethylene repeat unit is substituted by a larger fragment R. Polypropylene -[CH2-CH(CH3)]n- has the repeat unit -[CH2-CH(CH3)]. HashLearn is India's first on-demand tutoring app. Polymers are large molecules that have the same structural unit repeating over and over. For polyethylene, arguably the simplest polymer, this is demonstrated by the following equation. repeating unit. The examples of homopolymer are: polystyrene, polyethylene, polyvinyl chloride.. 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 polybutadiene is dissolved in styrene, which is then subjected to free-radical polymerization. (a) Draw the structure of the repeating unit in the superglue polymer. HDPE is composed of macromolecules in which n ranges from 10,000 to … 2501.0 . The molecular mass of the chain is just the product nMR. One repeat unit therefore has a molar mass of M(C 3H 6) = 42:08gmol 1. If the molar mass of the polymer is 3.5x10^5. For polyethylene, arguably the simplest polymer, this is demonstrated by the following equation. Dacron consists of polymerized units of the monomer ethylene terephthalate, with repeating (C 1 0 H 8 O 4 ) units. A polymer may be a chain of thousands of monomers, and so it is impossible to draw the entire polymer. Chemists tend to consider the repeat unit as -[CH2-CH2]- since this polymer is made from the monomer ethylene (CH2=CH2). A repeat unit or repeating unit is a part of a polymer whose repetition would produce the complete polymer chain (except for the end-groups) by linking the repeat units together successively along the chain, like the beads of a necklace. See the answer. 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. Polystyrene is made from the monomer styrene which is a liquid petrochemical. inter molecular forces (lower to higher). A single molecule of polystryene has the repeating unit -[CH2CH(C6H5)]n-, where n is the number of repeating units. ... (polyvinyl chloride), styrene (phenylethylene, polystyrene), methyl methacrylate (Plexiglas), and acrylonitrile (cyanoethylene, acrylic fibers). Table 15.1, p 427 in Brown lists the … 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. Here ethylene (ethene) is the monomer, and the corresponding linear polymer is called high-density polyethylene (HDPE). 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. A commercially important ABA-triblock copolymer is polystyrene-block-polybutadiene-block-polystyrene or SBS, a ... ,3-butadiene) (C and D). constitutes the repeating units. In many condensation polymers the repeat unit contains two structural units related to the comonomers which have been polymerized. The SPME fibre hosts in a Valco-tee unit sealed by a vespel ferrule. Teflon: Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene. Other than monodisperse polymers, there is normally a molar mass distribution caused by chains of different length. 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. 1,2-poly(1,3-butadiene) has a vinyl-type structure, where the substituent group (ethene) contains an unsaturated … A collection of products made from polystyrene: a cup, a guitar case, polystyrene carvings, and floating pool noodles. i know the answer is 1.1515 x 10^4 but how is it? [1] The difference C p – C v was calculated at 273°K. Solution for The repeat unit in polystyrene coffee cup has C6H5CHCH2. Trending questions. Bonus: Use your free doubt session & get a free formula book! The brackets contain the repeating unit. For example, in polyethylene terephthalate (PET or "polyester"), the repeat unit is -CO-C6H4-CO-O-CH2-CH2-O-. A single polymer molecule may consist of hundreds to a million monomers and may have a linear, branched, or network structure. You can see it in this 3-D model on the right or in the diagram below. To calculate the weight, I keep counting 8C & 7H. I'm trying to calculate the unit molecular weight of polystyrene. [3] (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. 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)]-. The repeating units are called monomers. 1. Complete the table to show the number of carbon and hydrogen atoms in an octyl group. 9. Polyethylene may be considered either as -[CH2-CH2-]n- with a repeat unit of -[CH2-CH2]-, or as [-CH2-]n-, with a repeat unit of -[CH2]-. As a foam, its two forms are expanded polystyrene (EPS) and extruded polystyrene (XPS). The aqueous sample is pumped by a HPLC pump from the sample vial through the extraction cell and … In fact, polymer molecules are often hundreds or thousands of monomer units long. Trending questions. Join. Did you know? The SPME fibre hosts in a Valco-tee unit sealed by a vespel ferrule. Get answers by asking now. [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. Still have questions? and found to be 2.0 cal./mole°. From Table 14.5, the acrylonitrile repeat unit contains 3 Carbon atoms, 1 Nitrogen atom and 3 Hydrogen atoms. Ask question + 100. 2. -[CH2-CHCl]n-, whose repeat unit is -[CH2-CHCl]-. Repeating units can also be made from two monomers. These two solvents are more water-like than hydrocarbon-like. Trending questions. Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. 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. 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 is a hydrocarbon polymer that is made of repeating units of styrene. (a) Compute the repeat unit molecular weight of polystyrene. Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. "Mer" originates from the Greek word "meros," which means a part. The numbers preceding the poly prefix designate the first and last carbon atoms of the backbone repeating unit. Propene's polymer repeat unit will look something like this: ### CH3 ### |- … d) Polypropylene has a repeat unit of (C 3H 6). A repeat unit (or mer), is not to be confused with the term monomer, which refers to the small molecule from which a polymer is synthesized.[5]. 552450.0 g/mol. It is an inexpensive resin per unit weight. 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. Repeating units can also be made from two monomers. Answer to: The repeat unit in a polystyrene coffee cup has the formula C6H5CHCH2. Discover (and save!) Solution (a) The repeat unit molecular weight of polystyrene is called for in this portion of the problem. C) + 8(A. how big … Join. 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. In your answer you should explain why the polymers formed in these two reactions are different. When the polymer is formed, the C=C double bond in the monomer is replaced by a C-C single bond in the polymer repeat unit, which links by two new bonds to adjoining repeat units. The styrene repeat unit contains 8 Carbon atoms and 8 Hydrogen atoms. 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. Thus, the molecular weight of the acrylonitrile repeat unit is: We connect students with top tutors from the IITs and BITS - instantly, anytime, anywhere. (b) The polymer shown above contains methyl groups (CH 3). Rather, the structure of a polymer can be condensed and represented as shown in the figure below. Ethanol and methanol are not very hydrocarbon-like and are not good solvents for polystyrene. Still have questions? 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 correct answer is 8C +8H. polystyrene, from Table 5.3, each repeat unit has eight carbons and eight hydrogens. your own Pins on Pinterest Extruded polystyrene (XPS) is commonly used in architectural models. 2. 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. For polystyrene, from Table 14.3, each repeat unit has eight carbons and eight hydrogens. Polystyrene is a synthetic aromatic polymer made from the monomer styrene. Solid polystyrene is transparent, owing to these large, ring-shaped molecular groups, which prevent the polymer chains from packing into close, crystalline arrangements. 2 pts Question 13 The repeat unit of polystyrene, which has 8 carbon atoms, and 8 hydrogen atoms. Edit: thread moved from non HW forum. The squiggly lines indicate that the polymer molecule extends further at both the left and right ends. Thus, m= 8(A. Thus, m = 8(AC) + 8(AH) = … Teflon: Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene. constitutes the repeating units. Polystyrene. Polymer molecules are very large compared with most other molecules, so the idea of a repeat unit is used when drawing a displayed formula. repeating unit, due to the double bond being on the C2 position. Ask question + 100. 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. For polystyrene, from Table 14.3, each repeat unit has eight carbons and eight hydrogens. Polypropylene and polystyrene are two types of commonly used polymers in the manufacture of plastic laboratory consumables. Thus, m = 8(A C) + 8(A H) = (8)(12.01 g/mol) + (8)(1.008 g/mol) = 104.14 g/mol (b) We are now asked to compute the number-average molecular weight. polystyrene and polypropylene are some examples of plastic in industry. Expanded polystyrene is commonly used in packaging. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. constitutes the repeating units. What is the value of n if the molecular mass of a single polymer chain is 1.5782 x 106 amu? Hydrogen is an explosive gas, oxygen supports combustion, why, when adding 2 hydrogen atoms to 1 oxygen atom, is the result an inert liquid? (Shakhashiri,2012) In Greek, polymer get w ‘ ’ ‘ ’ . 104.4 g/mol. HashLearn is the #1 platform to get online coaching for competitive exams. how big … (b) A simplified representation of polyvinyl acetate. What is the value of n if the molecular mass of a single polymer chain is 1.5782 10 6 A) 1.217 10 8 units. The examples of homopolymer are: polystyrene, polyethylene, polyvinyl chloride. (b) Compute the number-average molecular weight for a polystyrene for which the degree of polymerization is 25,000. 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. Get answers by asking now. 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 … 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. 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 …