Topic: Application of hydrocarbons

Target group

Elementary school student (grades 7. and 8.)

Core culliculum:

Primary school. Chemistry.

VIII. Compounds of carbon with hydrogen – hydrocarbons. Student:

4) observes and describes the chemical properties (combustion reactions) of alkanes; writes the equations for combustion of alkanes with high and low oxygen availability; finds and list information on the applications of alkanes;

6) on the basis of the observations describes the physical and chemical properties (combustion, bromine incorporation) of ethene and ethyn; searches for and uses information about their uses;

7) writes the equation of ethylene polymerization; describes the properties and applications of polyethylene.

General aim of education

The student discusses the use of hydrocarbons

Key competences

• communication in the mother tongue;

• communication in foreign languages;

• mathematical competence and basic competences in science and technology;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• what is the use of ethene and ethyne;

• explain the concept of polymerization reaction.

Methods/techniques

• expository

  • talk.

• activating

  • discussion.

• exposing

  • film.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers;

• sheets of gray paper;

• colored markers.

Lesson plan overview

Introduction

1. The teacher hands out Methodology Guide or green, yellow and red sheets of paper to the students to be used during the work based on a traffic light technique. He presents the aims of the lesson in the student's language on a multimedia presentation and discusses the criteria of success (aims of the lesson and success criteria can be send to students via e‑mail or posted on Facebook, so that students will be able to manage their portfolio).

2. The teacher together with the students determines the topic – based on the previously presented lesson aims – and then writes it on the interactive whiteboard/blackboard. Students write the topic in the notebook.

Realization

1. Students will get acquainted with the content of the abstract. Then the participants of the classes, working in pairs, ask each other about the knowledge of the abstract. With their own words, they explain the meaning of the terms: polymerization reaction, monomers, polymers.

2. The teacher announces a movie entitled „Examination of the speed of fruit ripening”. Instructs students to write a research question and hypothesis in the form provided in the abstract. Then it displays the video and the students record their observations and conclusions. Volunteers read them. The teacher encourages young people to discuss, referring to the presented conclusions.

3. The teacher divides the class into groups, distributes sheets of gray paper and colored pens. Students, using the Internet, textbook and electronic book, create infographics showing the use of hydrocarbons with the division into alkanes, alkenes and alkynes. Students are creating infographics can also use the editor of drawings in the abstract. After completion of activities, the group leaders present the effects.

4. Students, working individually or in pairs, carry out interactive exercises to check and consolidate knowledge learned during the lesson. Selected people discuss the correct solutions for interactive exercises. The teacher completes or straightens the statements of the proteges.

5. The teacher plays the abstract recording for all students. Participants listen carefully and give feedback on the difficulty of the text being heard using the traffic light method. Students are provided with green, yellow and red cards. While listening to the recording, they display the appropriate color for self‑assessment and to inform the teacher: green - I'm fine, I understand everything; yellow - I have some doubts; red - I do not understand anything, please help. The teacher responds depending on the needs of the students, deciding to repeat the recording, listen to the recording while following the text or translate the text.

Summary

1. The students consolidate the acquired information, discussing it with their nearest neighbors („tell your neighbor” method.

2. The teacher asks a willing student to summarize the lesson from his point of view. He asks other students if they would like to add anything to their colleague's statements.

Homework

1. Prepare 5 questions about the area that could be found on the test of the lesson.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Application of hydrocarbons

Crude oil, natural gas and black coal provide us with 85% of energy. These are raw materials for the production of fuels and many other products, including chemical and pharmaceutical industry. Methane is used as fuel in natural gas installations as a heating gas for the production of hydrogen, acetic acid and explosives. The mixture of propane and butane serves for heating in about 5 million households in Poland, but also for filling lighters, tourist bottles and as fuel for cars.

Among the unsaturated hydrocarbons, ethene and ethyne are most widely used. The first of these is used as a factor accelerating fruit ripening.

Unsaturated compounds under appropriate conditions can combine with each other to form long chains. This is polymerization reaction. It involves combining many molecules (monomers) into one molecule with a very long chain (polymer). The polymerization reaction is used to obtain polymers, i.e. synthetic materials that are compounds to produce everyday objects.

During polymerization of ethylene, double chemical bonds present in its molecules break and a molecule composed of many so‑called structural units is formed. The reaction product is polyethylene.

Polyethylene is a colourless or milky white, transparent solid. Thanks to its high strength, susceptibility to dyeing and forming and a relatively low price, it is used for the production of packaging films, bottles and containers for water, chemicals, bottle and food boxes, toys and small fancy goods. The widespread use of synthetic materials (e.g. disposable packaging) generates large amounts of waste, which in most cases is not biodegradable.

Types of polyethylene:

Most of the produced ethylene is processed into polyethylene and from ethylene due to various chemical processes – to other compounds.

The mixture of ethyne and oxygen due to the high combustion temperature is used in acetylene‑oxygen burners for cutting and welding metals. Acetylene (like ethylene) undergoes numerous chemical reactions leading to the formation of other compounds.

• Unsaturated hydrocarbons undergo appropriate polymerization reactions under certain conditions. As a result, small individual molecules – monomers – merge into long molecular chains (polymers).

• The polymerization reaction products are macromolecular compounds (polymers).

• Polyethylene is the product of the reaction of ethene polymerization.

• Most synthetic materials are not biodegradable.