SKP6024: ICT in Chemistry
Assignment 5: Simulation/Modelling using the 3E (Engage, Empower, Enhance) teaching model.
Group members: 1. NOR NOR AZILA AZILAWAT WATY Y BT AZ AZMI MI M20122001519 2. NURUL AZWA BT AHMAD NASIRUDDIN M20122001520 3. NU N UR SOFIA BT JAFAR
M20122001487
4. NURSH NURSHUHA UHADA DA BT BT NORD NORDIN IN M20122001482
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INTRODUCTION
SURFACE TENSION:
Surface tension is caused by a strong attraction of the particles. It is formed when the particles pull together.
. The cohesive forces between molecules down into a liquid are shared with all neighbouring atoms. Those on the surface have no neighbouring atoms above, and exhibit stronger attractive forces upon their nearest neighbours on the surface. This enhancement of the intermolecular attractive forces at the surface is called surface tension attractive forces are between unlike molecules, they are said to be adhesive forces. The adhesive forces between water molecules and the walls of a glass tube are stronger than the cohesive forces lead to an upward turning meniscus at the walls of the vessel and contribute to capillary action. action.
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PROPERTIES OF LIQUID
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The surface tension of liquid
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The difference of surface tension in water, oil, alcohol, soapy water and mercury.
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The relationship of temperature and intermolecular forces towards surface tension.
LEARNING OUTCOMES
At the end of the lesson, students students should be able to answer answer following question;
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What is the meaning of surface tension? What is the differences of surface tension in water, oil, soapy water, alcohol and mercury?
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What happen to the surface tension of liquid when we increase the temperature?
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What happen to surface tension of liquid when the molecules of liquid have stronger intermolecular forces?
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CHILDREN’S MISCONCEPTION ABOUT SURFACE TENSION
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All heavy or denser objects sink when placed in water.
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Tension (cohesion, adhesion) is uniform throughout a liquid.
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Boats, leaves, corks, float due to surface tension (these things float due to high buoyancy or low density)
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Do the water particles at the top interact with the pin in the same way as they do with other water particles (water particles bind differently to the pin; the pin is unable to penetrate the surface of the water, which causes it to float)
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Water is pushing up on the object
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Weight determines if an object will sink or float.
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Heavy objects always sink and light objects always float.
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A larger heavier object will not float as well well as a smaller lighter object of the same material.
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The amount of water will cause objects to float or sink better .
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The water drops form together and build up.
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The temperature will make a difference. Hotter water will be less than cold because the particles move faster.
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Pennies dropped into a jar full of water: shape of the glass distorts your view so you can put more in than you think. The lip of the glass lets the water go above the rim. The pennies are smaller than you think.
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Liquids are liquids and will all mix together
ENGAGE Justification.
Students are given several pictures as stimulant. Then t eachers will allow their student to think and give respond from the stimulant given .They have to observe and state whatever causing the phenomenon. In this activity, question is asked is to elicit their prior knowledge related to surface tension. Students are better if they are able to watch video about the actual phenomenon. phenomenon. Still picture can give wrong perception. From this step, teacher can see if there is any misconception problem based on the respond given by their students.
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What do you think the arrangement of molecules inside a liquid?
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Ans: Water is made of tiny molecules. These water molecules are highly attracted to to one another through natural forces forces (hydrogen bonding and van der Waals interactions). Since the water molecules are more strongly attracted to each other than they are to the air molecules found above the surface, the water molecules at the surface stretch out and bunch up to interact more readily with the water molecules found underneath. This stretching and bunching of the surface molecules causes a small "film" on the surface of the water, thus providing surface tension.
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How come the water striders walk on the surface of water? Can you explain about the below phenomenon?
Ans: The water strider was supported by acting up force. the water strider can walk on water because they are not heavy enough to break through the surface tension barrier. This allows for fish and other under water creatures to eat these bugs easily.
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Why does water beads of water produced on apple?
Ans: There is waxing or coating on apple s kin prevent water molecule from absorbed into it.
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What happen when you mix water and oil?
Ans: As daily observation, water cannot mix with o il. Oil will float on the surface of water. We can see clear boundary
between them.
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What is meniscus? Why is it meniscus of water differ from meniscus to mercury?
Water
Mercury
Ans: The curve in the upper surface of a liquid close to the surface of the the container or another object, caused by surface tension. The molecules of the water attract those of the container's, causing the surface of the water to cave downwards
Surface tension will attract the water solution to the molecules of the container thus lifting it up on the edges. Mercury, being much more dense has no such attraction because it is a liquid metal.
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How bubbles form? What makes bubble round?
Ans: The surface tension of water provides the necessary wall tension for the the formation of bubbles with water. The tendency tendency to minimize that wall tension pulls the bubbles into spherical shapes . When air is blown inside a bubble it is pushed outwards
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in all directions. This causes bubbles to become round. Bubbles are made made up of a thin film or skin of soapy water. This thin film/skin that holds the air inside of a bubble is stretchy and when the bubble is stretched; it pulls tightly.
EMPOWER Justification.
In this interactive activity, students will understand the basic nature of surface tension in liquids. The lesson involves of a discrepant event that will make students think critically about the phenomena of surface tension and correct any misconceptions. Students will developed their scientific skill like observing, classify and comparing the result. Moreover, it will allow the students to build their own understanding by extending the discrepant event to liquids of different surface tensions like soap water, oil and alcohol. Before start the experiment, experiment, certain questions being asked. Based on prior knowledge and experience, the scientist will make an educated guess as to the answer or outcome. This hypothesis will guide the design and execution of an experiment.
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ACTIVITY 1: Do surface tension exist? In this activity, you will do a simple experiment to determine whether surface tension is exist or not?
What the meaning of surface tension?
Ans: Surface tension is caused by a strong attraction of the particles. It is formed when the particles pull together.
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Start your experiment using the given apparatus. Please observe the phenomena and think about it. Related to your daily life.
By using following apparatus
1 clear plastic cup
Water
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standard size paper clip
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large paper clip
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Start your experiment.
What do you think will happen when I place this pin horizontally in the water?
Ans: Pin can float when it is placed into the water horizontally.
What do you think will happen when I place this pin vertically in the water? 10
Ans: Pin sinks when it is palced into the water vertically or pushed downward.
What do you think will happen when I push on the floating fl oating pin?
Ans: The pin will sink if push on the floating pin.
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Procedure.
1. Place water water in one one cup cup until until it is about about ¾ full. full. 2. Use your your device device to pick pick up a paper paper clip. clip. Do this by by squeezin squeezing g the ends ends of the device together a bit and placing them inside the paper clip. Then allow the ends to spread apart so that the tension of the ends pushes against the inside of the paper clip and holds it in place.
3. Carefully Carefully lower
the paper paper clip so that it lies
flat on the surface of the water. Slowly squeeze the device to release the paper clip.
What do you see? Why do you think a paper clip, which is denser than water, can stay on the surface of water?
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Ans: The paper clip is float on the surface of the water. This is because of something having to do with the water water molecules at the water’s surface, called surface tension. tension.
4. Predict Predict if several several objects objects will will sink or float ifif put in a tub tub or beaker beaker of water. water. (Objects: wood blocks, straw, penny, paperclip, straight pin, toothpick, needle)
Will each of these items sink or float? Ans: Sink: wood blocks, penny and straight pin.
Float: straw, paperclip, toothpick and needle.
What causes some objects to sink and others to float? What is water made of? Ans: Light objects float but heavy objects will float. Water has surface tension but surface tension can’t afford the heavy objects. So, heavy objects will sink.
You can also watch this video on http://www.middleschoolchemistry.com/multimedia/chapter5/lesson2 Justification: Students will discover by their own either the surface tension exist or not in different liquids. Moreover, this activity will develop their scientific skill.
ACTIVITY 2: Do surface tension varies on different liquid?
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In this activity, you will do an experiment to observe whether surface tension varies on different kind of liquid.
What is the difference of surface tension in water, oil, soapy water, ethanol?
Ans: The surface tension in water is stronger compare to oil, soapy water water and ethanol.
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Start your experiment using the given apparatus. Please observe the phenomena and think about it. Related to your daily life.
By using following apparatus and reagents
Coins
Water
Droppers
oil
soapy water
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Start your experiment.
How could we compare the surface tension of water with other liquids?
Ans: By doing experiments such as placing an equal number number of drops of each liquid on wax paper or comparing the the number of drops that can be added to the top of a coin.
What do you think will happen when we drop the liquids to the surface of a coin? Ans: The liquids will form a beads on the coin or the liquids will spreads out flat.
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Procedure.
1. Place Place the the coin coin on a paper paper towel towel..
2. Use a dropper dropper to drops drops of of water to the the surface surface of coin. coin. Count Count the drops drops until until the water overflows.
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3. Repeat Repeat the procedures procedures using using different different liquids; liquids; oil, ethanol ethanol and soapy soapy water. water.
Which liquid will form beads up on the surface of the coin?
Ans: Surface tension also enables water to bead ups or sometimes sometimes dome higher than the top of its container. container.
Which liquid can be added more drops to the coin?
Why there are different amount of liquid drops can be added on the surface of the coin?
Ans: This cohesiveness gives water its high degree of surface tension, allows it to form a nearly spherical "bead" when a single drop is placed on a flat, nonporous surface.In contrast, oils have few, if any, hydrogen bonds amongst their large, organic molecules. When oil is dropped onto a flat, nonporous surface, i t quickly spreads and forms a thin layer coating considerably more surface area than would a drop of water. Rubbing alcohol, on the other hand, is a mixture consisting of 70% isopropyl alcohol and 30% water. It does contain some hydrogen bonds within its structure, but not nearly as many as occur in pure water. Rubbing alcohol will form a bead when dropped onto a flat, nonporous surface, but the bead will be slightly flatter and larger in diameter than a
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corresponding bead of pure water.
Justification: Students can identify the differences of surface t ension for several differences liquids through this activity. They need to handle the activity slowly to get accurate amount of liquid drops on the surface of coin. This will teach them to do an experiment wisely.
ACTIVITY 3: Do surface tension of a same liquid varies at different temperature? (Heating (Heating the Needles' Bath Water)
In this activity, you will do an experiment to observe whether surface tension varies between cold water and hot water.
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Start your experiment.
What would happen if we placed the needle slowly on the icy water?
Ans: The needle will float on the surface of water. water.
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What do you think will happen to the needle when we heat the icy water? Ans: The temperature of icy water will rise. Needle will sink into the water
How could we compare the surface tension of hot water and cold water?
Ans: Water will lose its surface tension as we heat the water..
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Procedure.
1. the the appa appara ratu tus s
Hot plate
Thermometer
Needles
Ice-water
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2. Pour about about a litre litre of ice water water into into the beaker; beaker; put put the beaker beaker on top top of hot plate.
3. Place Place slowly the the needle needle on surface surface of water. water. Make sure sure it floating. floating. Lean the thermometer in the water in such a way that the temperature can readily be seen without having to move the thermometer.
4. Turn on on the heat. heat. While While watching watching the the thermomete thermometerr as to make make sure the the temperature is rising. Observe the needle.
What do you expect things that might happen to the needle?
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Ans: the needle will sink into the water.
Why at the needle floating we when put on the ice water at the first place?
Ans: at cold temperature molecules of water tend tend to stay closer. Provide a thin film to support the needle.
Why after we heat the ice water, after some time the needle sink?
Ans: When temperature arise, the molecules tend to move slightly apart. The film previous will torn.
Justification: In this activity, students will explore the effect of temperature on surface tension of a same liquid; water. They will observe whether the needle will sink or not eventually. Other than develop their experiment skill. They will learn to make prediction.
ACTIVITY 4: Observation on surface tension from video. 19
In this activity, you will watch a few videos related to surface tension. Log on to the given websites and answer the following question.
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Floating Water http://www.youtube.com/watch?v=u5AxlJSiEEs
1. What make make the card card stay stay at the mouth mouth of the the glass glass when the contain container er is placed upside down? down?
Ans: Pressure
2. Why must must fill fill the water until the water water flow flow out? out? Ans: To ensure there is no gas trapped in the glass.
3. Why the blue blue water water doesn’t doesn’t came came out from from the jar after after removing removing the the card?
Ans: There is due to surface tension effect.
4. Why the the blue water came out out from the jar jar after we we tilt the the jar?
Ans: Because the surface tension already been disturbed.
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Pepper and Water Science Magic Trick http://www.youtube.com/watch?v=2suY9h7xnKg
1. Why there there is nothing nothing happen happen when when you put put finger finger inside the water? water?
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Ans: Because the water contain stronger hydrogen bond, so the finger doesn’t effect it.
2. Why the pepper pepper move move away away from the the finger finger when you you dip the the dish detergent into the water?
Ans: Dish detergent will break the hydrogen bond and lowered the surface tension.
3. Does Does pep peppe perr hate hate soa soap? p?
Ans: No.
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Capillary action http://www.youtube.com/watch?v=d78OidfEqAs
1. How does does the liquid liquid immediat immediately ely rise rise up into the the capillary capillary tube tube when when we dip the capillary tube in a beaker of liquid?
Ans: This is because the capillarity due to properties of surface tension.
2. What are are the example examples s of capillary capillary action action given given in the the video? video?
Ans: 1.The rise of cell sap in tree and plant. 2. The absorptional absorptional ink in blotting paper.
3. According According to the the video, video, how to to prevent prevent mosquito mosquitoes es from breedi breeding? ng?
Ans: We can pour the oil into the water. So, it will lowered the the surface tension of water. Thus, when mosquitoes mosquitoes breed, the egg will sink and perish.
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Paper Clip in Water
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http://www.youtube.com/watch?feature=player_detailpa http://www.youtube.com/watch ?feature=player_detailpage&v=7DZP92X_n ge&v=7DZP92X_n2I 2I
1. What do you you expect expect to happe happen n if we add the the paper paper clip into into the water water inside inside the glass? Answer: the water will spilt out because penny displace the water. water.
2. What happe happened ned when when we continue continue adding adding paper paper clip clip into the the water water inside inside the glass? Answer: actually it will longer times for water to spill out because of surface tension of water water prevent the spillage.
ENHANCE
Justification: It teach students to give full attention during learning process. This activity will enhance their ability to collect information from various sources. Moreover, they will know the relationship of surface tension in their daily life. The knowledge that has been given to students will be test with some of question regarding the topic. This step will help teacher to see whether the lesson given by the teacher is success or not. It also help teacher to detect the level of understanding understanding of their t heir student. Beside that’s, it also help student to applied the knowledge with another situation.
The Application of Surface Tension In Daily Life 1. Therm hermo omete meter r A thermometer is a device that measures measures the temperature of things. things. The name is made up of two smaller words: "Thermo" means heat and "meter" means to
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measure. You can use a thermometer to tell the temperature outside or inside your house, inside your oven, even the temperature of your body if you're sick.
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C
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C
Why do we use mercury as indicator inside thermometer? Why at freezing point, mercury inside thermometer stay at 0oC and why does at boiling point, the mercury rise to 100oC
ANS: Surface tension for mercury is very high. It does not stick to the wall of capillary tube because of surface surface tension. If it stuck to the wall, the measurement of temperature would not have been correct.Capillary action is the result of adhesion and surface tension.. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward. Capillary action occurs when the adhesion to the walls is stronger than the cohesive forces between the liquid molecules.
http://www.mathisfun.com/meas http://www.m athisfun.com/measure/thermom ure/thermometer.html eter.html
Justification: Student can explore about thermometer and relationship between boiling point and freezing point. This activity activity can build up scientific scientific knowledge knowledge and manipulative manipulative skill among among students. Students can investigate and comparing the result between boiling point and freezing point.
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2. Washin Washing g Cloth Clothes es by by Using Using Soap Soap
The earliest recorded evidence evidence of the production of soap-like soap-like materials dates back to around 2800 BC in ancient Babylon. A formula for soap consisting of water, alkali, and cassia oil was written on a Babylonian clay tablet around 2200 BC. The Ebers papyrus (Egypt, 1550 BC) indicates the ancient Egyptians bathed regularly and combined animal and vegetable oils
with alkaline salts to create a soap-like substance. Egyptian documents documents mention a soap-like substance was used in the preparation of wool for weaving.
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Why we used soap or detergent to wash our clothes? Ans: Soap reduces the surface tension of water, which allows for water water to enter deeper into clothing for a better better cleaning.
Is that true washing your clothes with warm water is better than cold water? Why? Ans:Increasing the temperature of water reduces the the surface tension, whereas decreasing the temperature temperature increases the surface tension of water.
Justification: Students can deduce the result when used soap in washing clothes in warm water or cold water. This activity encourages students to curiosity towards what happened in washing clothes in warm water and hot water. Students also can build up scientific knowledge and manipulative skill.
3. Umbr Umbrel ella la and and Ten Tentt An umbrella or parasol (also called a brolly, parapluie, rain shade, sunshade, gamp, bumbersho bumbershoot, ot, or umbrolly) umbrolly) is a canopy designed to protect against rain or sunlight. The The word word para paraso soll usua usuall lly y refe refers rs to an item item desi design gned ed to prot protec ectt from from the the sun; sun; umbrella refers to a device more suited to protect from rain. Umbrella and tent is regarded as a sunshade and as a rain protector.
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Why when we used umbrella and tent, water does not absorbed and leak through the space of umbrella and tent? Is it true? Why is that when raining, the water falls in form of droplet? Beading of water on umbrella and tent: Waxing changes the surface properties of your umbrella. When the rains drops fall on your umbrella, they smoothly slide down to the ground keeping your umbrella neat and clean and untouched. Water tends to adhere weekly to the wax and strongly to itself. Water forms in droplets. Because water is attracted to itself, the molecules at the surface of the droplet stretch out to interact with other water molecules. This is also the reason why water droplets are spherical.
Justification: Students can know the uses of umbrella and tent to protect from raining and hot weather. Students use scientific skill by observing, predicting and investigation to know why water is not leak or absorb when used umbrella and tent. CONCLUSION These activities are designed to elicit any misconception among students regarding the topic of surface tension. Their teacher will try to alter or improved the prior knowledge of theirs. Read and explore the multimedia tutorial about surface tension Engage, empower and enhance learning process is used to carry out these activities. It included hands-on and mind-on activities. Moreover, students will use scientific skill such as observing, experimenting and predicting. At the end of lesson, the will used the concept of surface tension by related to our daily life activities. The teacher also can test whether their lesson is understood by all the students. students .
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List of References: 1. A. D. Grigoriev. Grigoriev. P. D. Grigoriev Grigoriev.. A. M. Dyugaev. Dyugaev. (2010). (2010). Surface Surface levels levels and their contribution to the surface tension of quantum liquids. Journal of Low Temperature Physics. Physics. 163: 131-147
2. D.Ariel. D.Ariel. W. Aaron et al. al. (2001). (2001). Surface Surface tensio tension n. Boundless. Boundless. Get from https://www.boundless.com/chemistry/liquids-and-solids/liquidproperties/surface-tension/On properties/surface-tension/ On 2 April 2013.
3. K. Jim, G. G. Patti, and and M. B. Adam. Adam. (2013). (2013). Middle Middle school school chemist chemistry. ry. American American Chemical Society, Chemistry for Life. Get from http://www.middleschoolchemistry.com/lessonplans/ on 1 April 2013.
4. M.Bruce. M.Bruce. (2004). (2004). Participator Participatory y partnership partnership:: Engaging Engaging and empowerin empowering g to enhance environmental management management and quality of life? Social Indicators Research. Research. 71: 123-144
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5. P. Maiju. Maiju. A. Susan Susanna na et al. al. (2009). (2009). Surface Surface tensio tension. n. Get from from http://www.attension.com/surfacetension?_kk=surface%20tension %20measurement&_kt=f514b4eb-db0c-4593-94cf 8e83bdcc9742&gclid=CIKB8Kzaw7Y 8e83bdcc9742 &gclid=CIKB8Kzaw7YCFRFu6wodmhkA CFRFu6wodmhkAcg cg on 2 April 2013
6. http://serc.carleton.edu/sp/mnstep/activities/20827.html 7. http://www.homeofbob.com/s http://www.homeofbob.com/science/misconceptio cience/misconceptions/densitySurfTensi.html ns/densitySurfTensi.html 8. http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-
tension 9. http://www.chem.purdue.edu/gchelp/liquids/tension.html 10. http://hyperphysics.phy-astr.gsu.edu/hbase/surten.html
11. http://en.wikipedia.org/wiki/Thermometer 12. http://www.ehow.com/how_do http://www.ehow.com/how_does_5452223_ es_5452223_detergen__break_ detergen__break_surface_tension surface_tension
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