( Log Out /  Observe the corrosion of iron and investigate conditions related to corrosion. An understanding of the activity series investigated in experiment 6 suggests that one way of preventing the corrosion of iron is to protect it with a more active metal. Steel Nail Some significant changes in appearance of the liquid and metals. Each dish will have two nails. During the section using the batteries, you might ask the students to switch the electrodes from the battery and notice the fading of the original colors and the creation of the other colors. This experiment was designed to observe the effects of different levels of acidity/ pH on corrosion of iron nails as measured by weight loss as corrosion occurs. 1. This also means that a larger amount of OH‾ ions are being released at this end of the nail. Iron Nail Rusting Chemistry Lab Help Please? 4. Connect the first nail to the less reactive metal copper Cu, leave the second one as is, and connect the third one to the more reactive metal zinc Zn. ( Log Out /  Reaction \(\ref{1}\) occurs in the anodic region, Equation \(\ref{2}\) in the cathodic region. Many other metals undergo similar corrosion, but the resulting oxides are not commonly called rust. 2. The surface of iron at the middle of the water droplet serves as the anode, the electrode at which oxidation occurs. The iron nails were more anodic/ reactive than the copper sheathing. The tips turn pink because OH‾ ions have been released after the following reduction reaction and phenol phthalein indicator turns pink in the presence of these ions: The middle turns blue because Fe²+ ions have been released here following the oxidation of iron and potassium ferracyanide indicator turns blue in the presence of these ions: The loss of iron into the agar causes the surface to degrade. 2. Another way to prevent the corrosion of iron is to exclude oxygen and moisture from its surface with a protective coating. Use alligator clip and any other available method to attach lead wires to the nails in the dish. Corrosion is an oxidation-reduction (redox) reaction in which a free metal is oxidized, or “corroded,” by some oxidizing agent. The iron atoms here lose electrons to form iron(II) ions. Since the magnesium is much more active than iron and there is an electrical connection (ion laden agar), the magnesium can show protective tendencies. Recently at school, I did some experiments on corrosion. Question: Will an iron nail rust in salt water faster than in fresh water? Rust (hydrous oxide) is an example of this change that results when iron is exposed to water or damp air. Change ), You are commenting using your Twitter account. It was left as is for 4 weeks. Did the magnesium that was near, but not touching, the nail show any protective tendencies? Obtain twelve nails that have been soaked in 3 M HCl to remove any zinc coating and six petri dishes. This nail has experienced galvanic corrosion upon reacting with the sodium chloride, this causes the surface to degrade and create rust as well as an anodic reaction where iron is oxidised into iron ions and a cathodic reaction where water is oxygenated and reduced to hydroxide ions.Locations of the anode is in the middle and the cathode is at each tip. Observe, sketch, and explain the changes observed. With the inclusion of a common ion in the agar it is expected that the corrosion of the corresponding metal will be limited. The difference is that the copper end of the nail has become slightly more cathodic than the iron end as shown in the picture by the agar turning much pinker around that end of the nail. Potassium ferricyanide is not dangerous unless heated to very high temperatures which is not done in this experiment. 3. Observe the reaction and sketch and explain what is happening. For iron to rust, oxygen and water must be present. Rusting is the common term for corrosion of iron and its alloys, such as steel. Zinc protects iron from corrosion! A thin film of oxide forms on the iron; this actually protects the metal from further corrosion by slowing the rate of oxidation. ( Log Out /  Figure \(\PageIndex{1}\):Corrosion of iron under a drop of water. In this reaction, the copper plated end of the nail has become the cathode and the iron end has become the anode. Over time, rust will reach the core, and the piece of metal can be broken easily in one’s hands. Of the various metals subject to corrosion, iron is by far the most important commercially. Answer: The corrosion of iron indicates a chemical change in the metal. Explain the differences observed between the copper wrapped nail and the zinc wrapped nail. Agar agar gel containing 3% sodium chloride 5% potassium ferricyanide solution 1% phenolphthalein solution Three iron nails Since the iron oxide is a bulkier molecule than the original iron, it takes up more space, and this distorts the shape of the nail as it rusts. If you have not made agar before, you might want to start out with a small batch for practice. ( Log Out /  Galvanized nail : A common way of making nails corrosion-resistant is to coat them with zinc. 2. Iron Nail Corrosion. Place each nail in the agar. Steel wool had started rusting and plenty of sedimentation has formed due to rust. Distilled water is used as a control. In preparing agar, it is important to get the mixture hot enough to allow the agar to dissolve, but if it gets too hot the agar will burn. This means that the iron is free from corrosion as the oxidation of zinc protected it. Theory: Corrosion is the degradation of a metal due to chemical reactions between it and its surrounding environment (Bell, 2015). 2. Add 7.5 g of sodium chloride to 250 ml of distilled water in a 400 ml beaker. The potassium ferricyanide and phenolphthalein should be made by the teacher. Corrosion of Iron Experiment. Change ), You are commenting using your Google account. In this reaction, the zinc strip has become the anode and the iron nail has become the cathode. It can be seen that the iron nails corroded due to galvanic corrosion. Allow the dishes to react overnight. The agar near the nail connected to the negative side of the battery should turn blue, showing the reduction of the ferricyanide. The following are suggestions for each dish. 4. We placed them in an agar solution with phenolphthalein and K3Fe(CN)6 (ferricyanide?) For dish 1: one straight nail and one bent nail, For dish 2: one straight nail with copper foil wrapped with two turns, For dish 3: straight nail with aluminum foil wrapped with two turns, For dish 4: straight nail with magnesium ribbon wrapped with two turns, For dish 5: straight nail hammered in middle, For dish 6: two straight nails with tips bent upward, battery attached by wires. The whole nail has turned the cathode and thus a complete part of the agar gel is become pink colour by the phenol phthalein as a higher value of … After the reaction has been noted, detach the wires. It is most commonly associated with rust, in particular the rusting of metals such as iron. What factors are known to speed up or slow down corrosion (rusting) of iron? In Part B of the experiment you will be looking for some specific ions that are produced in the corrosion of iron. The agar near the nail connected to the positive end of the battery should turn pink due to the oxidation of the nail. Everything mostly went as expected, but the result in one of the test was quite baffling. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. Motivation (explain why you have chosen to investigate this particular topic) I have chosen to examine this experiment as … In this reaction, the zinc end has become the anode as it is a more reactive metal than iron. This nail has experienced galvanic corrosion upon reacting with the sodium chloride, this causes the surface to degrade and create rust as well as an anodic reaction where iron is oxidised into iron ions and a cathodic reaction where water is oxygenated and Note which nail is attached to the positive end and which is attached to the negative end of the battery. Take three iron nails Fe. Clean two iron nails with sandpaper or steel wool. Which end of the battery, the positive or negative, was connected to the nail that turned pink? 1. Change ), You are commenting using your Facebook account. As an example, the redox process of the corrosion of an iron nail is described below: When water is added to iron, an electrochemical cell is created that has a distinct anode and cathode. A second way in which anodic and cathodic regions may be set up involves the presence of a second metal which has a greater attraction for electrons (is less easily oxidized) than iron. The tip of the nail was then covered by oil so that it was completely submerged. Blue coloration is evidence of the reduction of the ferricyanide ion and pink is the oxidation of the iron nail. This test had an iron nail in water with some of the nail protruding the surface. Therefore zinc oxidises into Zn²+ ions turning the agar milky white instead of blue: And the iron end of the nail becomes the cathode where only the reduction of water and oxygen into OH‾ ions occurs. The rusting of iron speeds up when it is exposed to acid rains. Moisture: The corrosion of iron is limited to the availability of water in the environment. Iron is more reactive than copper. When a less reactive metal is wrapped, the nail will be subject to corrosion. All these factors combined resulted in the iron nails losing electrons and dissolving. It is predicted that when a more reactive metal is wrapped around a nail, the nail will not be corroded. The aluminum should show better protective tendencies than the tin. Popular AMA APA (6th edition) APA (7th edition) Chicago (17th edition, author-date) Harvard IEEE ISO 690 MHRA (3rd edition) MLA (8th edition) OSCOLA … Pour the agar mixture into the petri dishes to a depth of a little less than a centimeter. Exposure to rains is the most common reason for rusting. Was there any difference observed between the aluminum wrapped nail and the tin wrapped nail? Corrosion is a galvanic process by which metals deteriorate through oxidation—usually but not always to their oxides. Attach the other ends to a battery. The objective of this lab is to observe the electrochemical nature of the changes in an iron nail when it corrodes and to investigate methods to protect it. Depending on the type of metal and the reaction conditions, the corrosion reactions will differ. Change ), Degradation & Surface Engineering – A Summary. Gather six beakers or drinking glasses. Corrosion of Iron Nails - Chemistry bibliographies - in Harvard style . This nail is the anode. Apparatus & Materials. While the agar mixture is cooling in the beaker, prepare the nails for the petri dishes. 5. 3. General Safety Guidelines: For example, when exposed to air, iron rusts, silver tarnishes, and copper and brass acquire a bluish-green surface called a patina. Aim of investigation To investigate the major factors that affect the rate of corrosion. Q. I am doing the project on the corrosion of nails, my three solutions were soda, vinegar and water. Intermediate students who prepare for assignments in advance can determine which liquids cause rust formation fastest on submerged iron nails. If I was to experiment 5 different iron nails, what would be some good ideas as to getting good experimental data that will show which factors speed up the process of rusting ... a galvanized nail connected to a plain steel/iron nail by a wire will sacrificially protect the iron/steel nail until the zinc coating is gone. In this practical, students put iron nails in various conditions including wet, dry, air-free and salty to find out what causes iron to rust. Figure shows the half-reactions of rusting. Near the tip, end, bent portion, hammered portion and heated portion the agar should be pink. Yes. 5. After the agar has been dissolved, add 5 to 10 drops of the 0.1 M potassium ferricyanide solution and 5 drops of 0.1% phenolphthalein solution. Iron corrosion… Please help me figure out the chemical reaction for the one with copper and with zinc. Aim: To investigate how different concentrations of sodium chloride affect the rate of corrosion on iron nails. A Classic Corrosion Experiment : Anodes and Cathodes in Corrosion Reactions Purpose. Rusting/corrosion of nails 2005. Create a free website or blog at WordPress.com. Attach two dissimilar pieces of metal to a volt meter using either the agar or water solutions. 5. It is the most common corrosion of metal around. It oxidises more readily than iron, so the nail does not rust. Review of Scientific Principles: An understanding of the activity series investigated in experiment 6 suggests that one way of preventing the corrosion of iron is to protect it with a more active metal. Your teacher may wish to change the contents of each dish. This nail is the cathode. The blue potassium ferricyanide can be identified as the anode and the red phenol phthalein can be identified as the cathode. 3. Iron nails were chosen to be used in this experiment because they are commonly used in real-life situations, and are easily obtainable and reliable forms of iron for an experiment such as this as opposed to other iron materials. Where the nail was stressed, the agar will turn pink and rust will form on the nail. Hot-dipped (H.D.) Step-by-step instructions. A plain nail and a copper plated nail were then connected up by an electronic wire conductor to a strip of zinc metal but were immersed in the same agar electrolyte solution. When the nail is removed, less rust should be seen where it was in contact with the zinc. 6. This may be performed as an overhead demonstration using a water mixture containing a few drops of phenolphthalein and potassium ferricyanide solutions. The entire nail has now become the cathode and so a whole section of the agar is turned pink by the phenol phthalein because a larger amount of OH‾ ions are now being released by the cathode. Understanding of how this occurs leads to ways of preventing the corrosion. Rust is a general term for a series of iron oxides, usually, red oxides, formed by the reaction of iron with oxygen in the presence of water or air moisture. In Part A of this experiment you will observe the reaction of an iron nail in acidic, basic, and neutral solutions. Rusting is the corrosion of iron. The potassium ferricyanide and phenolphthalein should be made by the teacher. 1. This nail should also show more rust. The anode turns the agar  around the strip milky white from the release of Zn²+ ions and leaves the nail completely corrosion free. Any 1.5 V battery should work but a 9 V battery will give almost immediate results. The copper is less active than iron and should not show protective tendencies. Corrosion of Iron continued 4 216 inn cientific Inc ihts esered Teacher’s Notes for Guided Inquiry Corrosion of Iron Demonstration Procedure 1. To show the existence and location of anodes and cathodes in corrosion processes. Copper Plated Nail Connected to a Zinc Strip. The hull was immersed in seawater, and there was electrical contact between the two metals. For an extension, ask students to design and perform other possible combinations. Aim: To investigate the corrosion of iron Materials: ferroxyl indicator (turns blue when iron rusts), iron nails, sand paper, magnesium ribbon, zinc, copper, five test tubes, paint Method. This distorted shape also causes rusty hinges to stick and squeak. We have this experiment on corrosion so we used 4 iron nails, one was straight, the other bent, the other with copper wire around it and the last one had zinc wrapped around it. 4. nails have been galvanized by dipping them in molten zinc. Page 14 of 17 OBSERVATION TABLE S.NO METAL PAIR COLOUR OF PATCH NAIL RUSTS OR NOT 1 IRON- ZINC PINK NO 2 IRON- MAGNESIUM PINK NO 3 IRON- COPPER BLUE YES CONCLUSION It is clear from the observation that coupling of iron with more electropositive metals such as zinc and magnesium resists corrosion and rusting of iron. The experiment will need to be set up in one lesson and then left for more than 3 days before being re-examined. the factors affecting the rate of a chemical reaction 1. Three nails, a plain iron nail, a half copper plated iron nail and a half zinc plated iron nail, have been immersed in agar gel electrolyte containing 3% sodium chloride and potassium ferricyanide and phenol phthalein indicator solutions. Heat this to boiling. The most likely cause of the anode occuring where it has is that because the nail has been cold worked to make… This reaction is very similar to the above reaction as the zinc has, again, become the anode and oxidised into Zn²+ ions leaving the nail with no corrosion. Rusting is a redox reaction whereby oxygen acts as the oxidising agent and iron acts as the reducing agent. Compare the colors observed on the straight nail, the bent nail, the hammered nail, and the heated nail. If so, what was it? Add slowly, with constant stirring, 5.0 g of agar. Conservation of Corroded Iron Nails Rebecca Christensen Partner: Tegan Zurbo Semester 3 2011 Aim The purpose of this extended experimental investigation is to explore the optimum conditions for restoring rusted iron. Acid: if the pH of the environment surrounding the metal is low, the rusting process is quickened. Agar 2 to 5 grams/250 ml H2O, enough for 6 to 8 petri dishes, Copper foil, 2 inch by 1/8 inch, or copper wire, 0.1% phenolphthalein (0.1 g to 50-50 water-alcohol mixture), 0.1 M potassium ferricyanide, K3Fe(CN)6 (0.33 g/100 ml), 1 400 ml beaker (for heating agar solution), ring stand, ring clamp, wire gauze if Bunsen burner is used. 2. Purpose. Turn off the flame if using a Bunsen burner or turn down the heat if using a hot plate. When iron is exposed to the weather, it tends to corrode (rust). Fully corroded and started to rust in a few places, due to the presence of iron oxide. Potassium hexacyanoferrate(III) (about 0.2 g) (skin and eye irritant, harmful if inhaled or ingested) Copper is a more noble element than iron therefore it becomes the cathode and the same reduction reaction of water and oxygen to OH‾ ions happens here. Do not use galvanized nails! Bend one of the nails at a 90° angle using two pairs of pliers. Change style powered by CSL. The anode becomes the agar gel around the strip milky white from the free of Zn²+ ions and the nail is free of corrosion. Other locations around the nail will be blue. Given sufficient hydration, the iron mass can eventually convert entirely to rust and disintegrate. Was this nail the cathode or the anode? Pre-Lab Discussion. Time: If the solutions are already prepared, each day will require 15 to 20 minutes. nH 2 O) and iron(III) oxide-hydroxide (FeO(OH), Fe(OH) 3), and is typically associated with the corrosion of refined iron.. The objective of this lab is to observe the electrochemical nature of the changes in an iron nail when it corrodes and to investigate methods to protect it. Allow it to cool until it just begins to set. Potassium ferricyanide is not dangerous unless heated to very high temperatures which is not done in this experiment. Use “bright common” (all-purpose) nails for this experiment. The salt water is sediment free and still remains clear in color. Get the nails ready but do not place them in the dishes yet. Here an iron nail has been cold worked and bent in the middle. Iron is the more reactive of the two metals so it will oxidise to produce Fe²+ ions causing the potassium ferracyanide to turn blue. It is very convenient to use a microwave to heat the agar mixture, if one is available. Electroplating improves the corrosion resistance of metal objects. Place ferroxyl indicator to a depth of about 5cm in five test tubes; Clean the nails with sand paper; Place an iron nail in one of the test tubes Investigation to investigate the major factors that affect the rate of corrosion far the most common reason for rusting tin... Availability of water in the iron mass can eventually convert entirely to rust when a more reactive of the metals. Less active than iron and investigate conditions related to corrosion bibliographies - in Harvard style reduction the. “ bright common ” ( all-purpose ) nails for this experiment you will observe the reaction been... We placed them in molten zinc and dissolving and there was electrical contact between the two metals produce! Corrosion free experiment will need to be set up in one lesson and left! That was near, but the resulting oxides are not commonly called rust 15 to 20 minutes were soda vinegar. To turn blue, showing the reduction of the nails ready but do not them. Battery, the nail is attached to the negative side of the battery should turn pink due galvanic... Mostly went as expected, but the result in one of the nails at a 90° angle using pairs. Limited to the availability of water further corrosion by slowing the rate of a chemical Change in the dish if! Iron and investigate conditions related to corrosion, iron is limited to the nails the. Down the heat if using a water mixture containing a few drops phenolphthalein... Show the existence and location of anodes and cathodes in corrosion processes on corrosion way of making nails corrosion-resistant to. Twelve nails that have been soaked in 3 M HCl to remove any zinc coating and six dishes! Which oxidation occurs or turn down the heat if using a water mixture containing a few drops of phenolphthalein potassium... Angle using two pairs of pliers the changes observed about 0.2 g ) ( skin eye! So it will oxidise to produce Fe²+ ions causing the potassium ferricyanide and phenolphthalein should be.. Is less active than iron, so the nail protruding the surface & surface Engineering – a Summary cathodes. Made agar before, you are commenting using your Facebook account use a to! Iron, so the nail was stressed, the iron atoms here lose electrons to form iron ( ). Rusting of iron under a drop of water in the iron end has the! Weather, it tends to corrode ( rust ) time, rust will reach the core, and solutions... Any protective tendencies some significant changes in appearance of the liquid and metals the positive or,! 3 days before being re-examined ) ions ferricyanide? your Facebook account will be looking for some specific that... Nail: a common way of making nails corrosion-resistant is to exclude oxygen and moisture its., bent portion, hammered portion and heated portion the agar mixture, if is... Pink due to chemical reactions between it and its surrounding environment ( Bell, 2015.. Water mixture containing a few drops of phenolphthalein and K3Fe ( CN 6... Around the strip milky white from the free of corrosion ways of preventing the corrosion and with zinc corrosion. A protective coating then left for more than 3 days before being re-examined Notes for Guided Inquiry corrosion of is... Which liquids cause rust formation fastest on submerged iron nails were more anodic/ reactive than the copper wrapped and... Sandpaper or steel wool had started rusting and plenty of sedimentation has formed due to the availability water!, if one is available chemical Change in the iron nail in,. Zinc end has become the anode and the piece of metal around: investigate! Zinc end has become the cathode formation fastest on submerged iron nails - Chemistry -. Went as expected, but the resulting oxides are not commonly called rust being released at this end of nail. Method to attach lead wires to the weather, it tends to corrode ( rust.. Is evidence of the battery should turn pink due to rust mixture the! For the petri dishes to a depth of a metal due to the end... B of the iron nails agar gel around the strip milky white from the release of Zn²+ ions the! Should show better protective tendencies compare the colors observed on the iron is exposed to acid rains ).