Polymer

Enrichment Corner 4:Plants synthesise glucose through photosynthesis and glucose is a simple sugar with the formula C6H12O6. The structural formula for glucose is shown in Figure 2.Glucose is a monomer for starch that is useful as an energy source. Based on the structure of glucose, explain the polymerisation process that takes place among glucose molecules … Read more

Question 1:Polymerisation is a process of producing long chain molecules from monomers.(a) Draw the monomers for polyvinyl chloride (PVC).(b) What is the type of polymerisation involved in the production of PVC?(c) The table below shows the information about polyethene and its monomer.(i) State the use of polyethene.(ii) Explain the difference between the physical state of … Read more

Question 1:What is meant by synthetic rubber? Answer:A polymer that is elastomeric in nature or elastic polymer. Question 2:Surgical gloves can be manufactured by using natural rubber or synthetic rubber.(a) Name a synthetic rubber that can be used to manufacture surgical gloves.(b) How are the characteristics of natural rubber surgical gloves different from those produced … Read more

Question 1:Name the polymer for natural rubber. Answer:Polyisoprene Question 2:The presence of acid in latex causes latex to coagulate. (a) State the function of acid in the coagulation process of latex.(b) Describe the coagulation process of latex. Answer:(a) The presence of hydrogen ions, H+ in the acid neutralises the negatively charged protein membrane.(b) – Hydrogen … Read more

Experiment 4B (Investigating the Elasticity of Vulcanised Rubber):Aim: To investigate the elasticity of vulcanised and unvulcanised rubber.Problem statement: Is vulcanised rubber more elastic than unvulcanised rubber?Hypothesis: Vulcanised rubber is more elastic than unvulcanised rubber.Variables:(a) Manipulated variable : Vulcanised and unvulcanised rubber strips.(b) Responding variable : The elongation of rubber strips when the weight is removed.(c) … Read more

Laboratory Activity 4C (Vulcanisation of Rubber):Aim: To produce vulcanised rubber.Materials: Latex, ethanoic acid, CH3COOH and solution of disulphur dichloride, S2Cl2 in methylbenzene, C7H8 solution.Apparatus: Beaker, dropper, retort stand, white tile, clip, knife and measuring cylinder.Procedure:1. Measure 25 cm3 of latex using a measuring cylinder and pour it into a beaker.2. Drop 3-5 drops of ethanoic acid, … Read more

Activity 4E:1. Carry out the activity as a group discussion.2. Present the answers for the following questions using an i-Think map.(a) Classify the following substance into coagulant and anti-coagulant for latex.(b) Explain why latex that coagulates naturally takes a longer time compared to when a coagulant is added.(c) Using a diagram, describe the mechanisms that … Read more

Laboratory Activity 4B (Producing a Product from Latex):Aim: To produce a product from latex.Materials: Latex and ethanoic acid, CH3COOH.Apparatus: Beaker, glass rod and measuring cylinder.Procedure:1. Measure 200 cm3 of latex using a measuring cylinder and pour into a beaker.2. Measure 5 cm3 of ethanoic acid, CH3COOH using a measuring cylinder and pour it into the … Read more

Experiment 4A (Coagulation of Latex):Aim: To study the coagulation process in latex and how to prevent coagulation.Problem statement: Does acid cause latex to coagulate and alkali prevent latex from coagulating?Hypothesis: The presence of acid in latex causes latex to coagulate, while the presence of alkali prevents the coagulation of latex.Variables:(a) Manipulated variable : Ethanoic acid, … Read more

Activity 4D:Discuss the following questions in pairs and write down the answers in your notebook.(i) What is the IUPAC name for the monomer of natural rubber?(ii) Explain the characteristics of rubber particles that prevent rubber from coagulating.(iii) Rubber gloves are among the products made from natural rubber. Explain the characteristics of natural rubber that enable … Read more