Dissolving pennies in hydrochloric acid 3. More links and info in full description ↓↓↓ Featuring Sir Martyn Poliakoff and Neil Barnes. )→Cu(NO +) 0(-. If a penny is scratched and then soaked in hydrochloric acid, it is possible to dissolve the zinc disk, leaving only a thin, hollow shell of copper. United States pennies have been minted in the past few years with the less expensive metal zinc as a center filler and the more expensive copper metal as an overall cover. Jul 22, 2020 · When cleaning a penny, the hydrochloric acid produced by the mixture of salt and vinegar dissolves a thin layer of copper on the penny. The key is to use hydrochloric acid (HCl). To do this we will dissolve the penny in concentrated nitric acid: Cu (s) + 4 H + (aq) + 2 NO 3 − (aq) → Cu 2+ (aq) + 2 NO 2 (g) + 2 H 2 O (l) Zn (s) + 2 HNO 3 (aq) → Zn 2+ (aq) + 2 Jul 16, 2021 · When a copper penny is put into a beaker of hydrochloric acid it just sits there. \mathrm{Zn}(s)+2 \mathrm{HCl}(a The reaction of a copper penny (minted pre-1982) and concentrated nitric acid (15 M) is shown. Removal of Zinc from Pennies Objective: The different reactivities of copper and zinc to hydrochloric acid will be used to separate the two metals in a post-1983 penny. This substance is any acid. Jan 14, 2025 · Why can a solid copper penny be dissolved in nitric acid, but not in hydrochloric acid? Modern pennies are made from zinc metal plated with copper. Sulfuric acid has a medium oxidizing ability and will dissolve copper over time. Nitric acid dissolves pennies in seconds. 5% of copper (Cu) per coin. So, the salt is added to speed up the process. A pre 1982 penny is mostly copper and doesn't react with HCl. For instance, a salt and vinegar solution can clean an old penny by removing its copper oxide, rust stains from metal fixtures, or grime build-up from appliance surfaces. But when \muriatic acid is combined with nitric acid to treat gold, the gold dissolves. It will remove verdigris, sure. Nothing happened. You take a post-1982 penny, score the copper surface to expose the zinc interior, react the zinc with acid, and are left with a hollow copper penny. After that i heated acid in water path to 80 C and waited. 484 g and then makes several scratches in the copper coating to expose the underlying zinc). This cleaner must contain Hydrochloric acid (HCL). Why does the copper dissolve? Aug 27, 2020 · Salt is added to react with the vinegar and produce a stronger acid to clean the pennies. ) CAUTION: DILUTION OF SULFURIC ACID MUST ALWAYS BE DONE BY POURING ACID INTO WATER IN A FINE STREAM, NEVER by pouring water into concentrated sulfuric acid, because sudden heating, expansion and spattering can occur! May 7, 2013 · We started out with our book to guide us as well as a bit of sandpaper, table salt, white vinegar a handful of post-1982 pennies. Previous topic - Next topic. 0 Members and 1 Guest are viewing this topic. But zinc sulfate is not commonly found in drug stores, hardware stores, garden stores, etc. In beaker # 4, when you mix the vinegar and salt, you make hydrochloric acid. Which acid can dissolve glass? Hydrofluoric acid 3. After soaking the penny in the acid, rinse it with clean water and you’ll be left with a shiny penny. Question: Since 1982, pennies changed from being pure copper to a zinc with a copper coating. When cleaning a penny, the hydrochloric acid produced by the mixture of salt and vinegar dissolves a thin layer of copper on the penny. Suppose a penny In order to determine the mass percent’s of copper and zinc in pennies, you will need to dissolve penny samples in concentrated nitric acid solution. The student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the HCl (the copper remains undissolved): A student determines the mass of a penny to be 2. And not strong enough to dissolve metal. 1°C. 88 L at a total pressure of 770. Oct 31, 2024 · In order to use spectrophotometry and Beer's Law to determine how much copper was contained on our penny, we need to make a solution of copper from the penny. Once the gold is dissolved, filter, add about one milliliter of sulfuric acid, then add sodium or potassium metabisulfite to precipitate the gold from solution. Immediately after submersing the coin, the solution turned yellow: This is a result of dissolved iron- and copper oxides. The balanced equation for this reaction is: \( Zn (s) + 2HNO_{3} (aq) \rightarrow Zn(NO_{3})_{2} (aq) + NO (g) + 2H_{2}O (l) \) When the penny is placed in hydrochloric acid: Copper will not dissolve in hydrochloric acid as the reduction potential • Acids (Hydrochloric acid, Sulfuric acid, Nitric acid, Vinegar, Lemon and Tomato juices, etc. Jan 15, 2017 · This is an easy chemistry project that uses common materials. It will also remove patina/toning and attack the metal surface directly. • Beaker • Liquid toilet bowl cleaner from a supermarket. Zinc dissolves in hydrochloric acid, but copper does not. What happens to the zinc in the penny when the coin is placed in nitric acid? Hydrochloric acid? A copper penny can be dissolved in nitric acid but not in hydrochloric acid. Find step-by-step Chemistry solutions and the answer to the textbook question The zinc in a copper-p lated penny will dissolve in hydrochloric acid if the copper coating is filed down in several spots (so that the hydroc hloric acid can get to the zinc). , and sulfuric acid is perhaps even more wicked than hydrochloric acid to Hydrochloric acid reacts with zinc but not with copper to form hydrogen gas (H2) and zinc chloride (ZnCl2). Then i placed coin into 23% nitric acid. What kind of acid makes copper turn brown? The most common weak acid we have around I dissolved a piece of zinc metal in hydrochloric acid to make ZnCl2 and a dark copper colored spongy mass remained. So i put it to 40% sulfuric acid. The old pennies remain untouched and the zinc of the new pennies dissolves, leaving the copper cladding. Ira Remsen (1846-1927) was an influential chemist in America. Hydrochloric acid will dissolve iron- and copperoxides, but it's relatively harmless for silver of high purity. Red-brown nitrogen dioxide is generated and some of the copper dissolves to form a blue solution of copper(II) nitrate. The student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the HCl (the copper 2. What happens to a modern penny when it is placed inside a bath of hydrochloric acid after the penny is scratched, exposing some of the zinc? Mar 1, 2017 · Hydrochloric acid fumes will rust every piece of steel in your house. #shorts A copper penny can be dissolved in nitric acid but not in hydrochloric acid. The zinc within a copper-plated penny will dissolve in hydrochloric acid if the copper coating is filed down in several spots (so that the hydrochloric acid can get to the zinc). Your materials are as follows: A Post-1982 Penny; Hydrochloric Acid; Tweezers (for Penny Retrieval) Jul 7, 2022 · Strong acids typically dissolve metals, but some metals are stable enough to resist the effects of acid. Per gram of copper, 3 ml of hydrochloric acid (33 percent) or 1. Hydrochloric acid reacts vigorously with metals that are above hydrogen in the reactivity series, such as zinc, to produce metal chlorides and hydrogen gas. post-1982 US pennies (metal composition changed in this year) muriatic acid (from a hardware store) Mar 5, 2015 · A common experiment in US high schools is to notch pennies with a file and add them to an HCl solution. ) It is a common myth that Coke dissolves nails or coke dissolves pence. What are the products of the reaction? Newer pennies contain a mixture of zinc and copper. What happens to a modern penny when it is placed inside a bath of hydrochloric acid after the penny is scratched, exposing some of the zinc? Apr 13, 2005 · I tryed to dissolve nickel plating on coin. But a zinc penny will quickly dissolve. This is because of the presence of hydrochloric acid in our stomach. After 2 days, the Apr 9, 2021 · Removing rust can be done effectively at home through abrasion, dissolving it in acid, use pastes, or electrolysis. 0 mL of 6. a) Calculate the reduction potentials to show why this is so, using the following equations: Cu(s) + 2H+(aq) does not react 3Cu(s) + 2HNO3(aq) + 6H+(aq) → 3Cu2+(aq) + 2NO(g) + 4H20(1) b) Newer pennies contain a mixture of zinc and copper. The reaction forms hyd Nov 2, 2023 · A copper penny can be dissolved in nitric acid but not in hydrochloric acid. Pure acetic acid (concentrated vinegar) will do the same. A Penny Dissolving in Acid Video A trick that is a bit neater, is to scratch through the copper of a newer penny, put it in Hydrochloric Acid, and the zinc will Apr 19, 2012 · In this experiment, we will be dissolving the zinc out of a penny so that all you are left with is the copper coating. Still using the tongs, move the pennies through the water to rinse them. Join us for free science lessons and sc Dec 1, 2007 · To clean the pennies, you need a strong acid, such as hydrochloric acid. The student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the HCl (the copper remains undissolved): Zn(s) + 2 HCl(aq)-----> H2( g) + ZnCl2(aq) The zinc in a copper-plated penny will dissolve in hydrochloric acid if the copper coating is filed down in several spots (so that the hydrochloric acid can get to the zinc). Using tongs, transfer both pennies from the hydrochloric acid solution to a 250-mL beaker of water. Oct 16, 2011 · Hydrochloric and phosphoric acid don't oxidize metals well and won't dissolve copper. Sep 11, 2011 · If you want to remove the Zinc from a plated penny and leave the Copper shell, file a small spot on the rim to expose the Zinc. Or 3M to 6M Hydrochloric acid solution. 899 L at a total pressure of 791 mmHg. 3 torr. 482 g and then makes several scratches in the copper coating (to expose the underlying zinc). Observations of pennies: Pre-1982 Penny Post-1983 Penny . What happens to the zinc in the penny when placed in nitric acid? Hydrochloric acid? A popular classroom demonstration consists of filing notches into a new penny and soaking the penny in hydrochloric acid overnight. Why is vinegar and salt mixture suitable to clean pennies? Copper oxide dissolves in the presence of an acid. Coins retained in the stomach will release a number of heavy metals well known to cause dose-dependent poisoning. Study with Quizlet and memorize flashcards containing terms like purpose, safety, from 1864-1982 how much copper was in a penny and more. In this classic demonstration, the experience Ira Remsen had with nitric acid can be reenacted. Then place the penny in Hydrochloric acid. Concentrated Phosphoric Acid dissolves glass and many rocks at 200C, and may have some effect on diamond. If there was any leftover zinc in your product at the end of your experiment, it could have been dissolved with hydrochloric acid, leaving the copper unharmed. 5% zinc and a 2. Feb 15, 2000 · The authors analyzed corrosion after exposure to hydrochloric acid in four types of coins: three silver-colored coins (a quarter, a nickel and a dime), six pre-1982 pennies that were worn but not Apr 10, 2019 · A strong acid, like HCl, reacts faster than a weak acid - like acetic acid (which is the main acid component of vinegar). This dissolves the copper compound. The collected gas occupies a volume of 0. Subscribe to Midnight Science Club 🌙 and enjoy a backstage pass to science! For us, science and fun go hand-in-hand. Jul 14, 2017 · Two different pennies are compared in their reaction with concentrated hydrochloric acid. Repeatedly allowing copper oxide (the green stuff that looks like dirt on the penny) to form and “cleaning” it will slowly but surely reveal a quick-to-dissolve zinc core. Does Coke dissolve rust? Get rid of rust: If you have any rust stains or tools covered in rust, Coca-Cola will eat away at the rust for you. 5 g of zinc and is soaked in 20. The reaction between the acid and the zinc is 2 H+ (aq) + Zn(s)¡ H2( g) + Zn2 + (aq). When salt is added to the vinegar, it is able to clean the pennies. A n • Lots of pennies, 1983 or newer (Note: You may legally experiment and alter your coins as long as you do not misrepresent the coin's true value. The student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and HCl (the copper remains undissolved) Zn(s) + 2HCl(aq) → H 2 (g) + ZnCl 2 (aq) The student collects the hydrogen produced over water at 22. Suppose a penny The zinc in a copper-p lated penny will dissolve in hydrochloric acid if the copper coating is filed down in several spots (so that the hydroc hloric acid can get to the zinc). Zinc is cheap. We need a substance that destroys it. Be careful with having the lid on during the reaction, either release pressure often, or use no lid at all in a well ventilated space. Floating Pennies. Nitric acid is A copper penny can be dissolved in nitric acid but not in hydrochloric acid. What happens to the zinc in the penny when placed in nitric acid? Hydrochloric acid? Apr 23, 2021 · I immersed the coin in 30% hydrochloric acid. If the zinc is exposed and a penny is dropped into 4. Why can a solid copper penny be dissolved in nitric acid, but not in hydrochloric acid? Modern pennies are made from zinc metal plated with copper. Still nothing happened. A penny with a scored edge allows the HCl to react with the int; The zinc within a copper-plated penny will dissolve in hydrochloric acid if the copper coating is filed down in several spots (so that the hydrochloric acid can get to the Mar 19, 2025 · Zinc dissolves in hydrochloric acid, but copper does not. Aqua regia means “royal water” because this mixture of hydrochloric and nitric acid can dissolve noble metals, such as gold and platinum. Resistant Metals. )+2NO 0(2)+2H 0O(3) Sep 11, 2023 · A solid copper penny can be dissolved in nitric acid and not hydrochloric acid because nitric acid can oxidize copper to form soluble copper nitrate while hydrochloric acid cannot. Wear chemical splash goggles, Aug 26, 2014 · I am fascinated by the chemistry of pennies. Answer to 3. What happens to the zinc in the penny when placed in nitric acid? Hydrochloric acid? Dec 27, 2023 · How do we then clean our coins marred by black copper (II) oxide (CuO)?. On average, there is about 3. The use of nitrile gloves is recommended. Hollow Penny Materials. The combination of a bubbling green solution and noxious brown gas that changes the color of an acid base indicator enlivens any discussion on redox chemistry. He founded the chemistry department at Johns Hopkins and initiated the first center for chemical research in this country. If you don’t know what an acid is, don’t worry; in fact, it’s enough for you to know that an acid, HA, is a substance that, in solution, releases H + ions and A –, where H + is the positively charged hydrogen ion, and A – indicates any negatively Jul 26, 2020 · Which acid can dissolve diamond? If you put stomach acid in a stainless steel pressure tank and heated it to 200-300C, you might dissolve a little of your diamond. Also, carbonic acid – which is what gives Coca-Cola its dissolving qualities – is a weak acid. Suppose a penny contains 2. Hydrochloric acid (salt and vinegar solution) is also used as a household cleaner to remove dirt, grease, rust, and mineral deposits. Dissolving a penny in nitric acid is one of the most visually stimulating chemistry reactions I have ever seen. Write an unbalanced chemical equation to illustrate the reaction of zinc metal with hydrochloric acid, which produces dissolved zinc chloride and evolves gaseous hydrogen. But, the results Pennies are copper-plated zinc coins, with about 2. Zinc readily reacts with hydrochloric acid, replacing the hydrogen atoms to make aqueous zinc chloride and hydrogen gas. The react ion between the acid and the zinc is 2 H + ( a q ) + Z n ( s ) H 2 ( g ) + Z n 2 + ( a q ) 2 \mathrm{H}^{+}(a q)+\mathrm{Zn}(s) \longrightarrow \mathrm{H}_{2 Mar 16, 2020 · Because new pennies are made of zinc coated with copper, and hydrochloric acid dissolves zinc and not copper, the inside of the penny is dissolved by the acid, while the outer copper shell remains. RO Part A Modern pennies are composed of zinc coated with copper. I prefer aqua regia being 4 parts hydrochloric acid and 1 part nitric acid. Studies to evaluate their toxicity and absorption are needed to optimize treatment. The student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and HCl (the copper remains undissolved) Zn(s) + 2HCl(aq) → H 2 (g) + ZnCl 2 (aq) The student collects the hydrogen produced over water at 20. For example, metallic copper is known to dissolve in concentrated nitric acid by going through the following reaction: Cu(s)+4HNO + (-. The acid won't touch the Copper but it will dissolve the Zinc from inside, leaving a hollow shell of Copper. 96 L at a total pressure of 765. In this video, I drop a penny into nitric acid and I let it react until it completely disappears. What happens to the zinc in the penny when placed in nitric acid? Hydrochloric acid? zinc on copper would be to use an electrolyte consisting of a zinc salt, such as zinc sulfate, dissolved in water, with a touch of sulfuric acid to improve the conductivity. The source of the zinc metal was melted pennies. We did a lab on pennies post-1982 and pre-1982. Sometimes the copper cladding also dissolves and sometimes a considerable amount of the old penny dissolves. There are myths and rumors that the Coca Cola drink can actually dissolve a T-Steak in 2 days. You may ask: Why would anyone want to do this? Suppose you were dissolving a metal such as zinc with hydrochloric acid. In the context of the given problem, hydrochloric acid is responsible for reacting with the zinc core of the penny, dissolving it and leaving behind the copper shell. 10 grams of zinc in each penny. Started by Abhay, July 31, 2013, 11:01:11 AM. Muriatic acid is going to screw up your septic tank, possibly rupturing it. An acid capable of dissolving metal found in a penny or a nail is hydrochloric acid. Copper is often associated with noble metals for its resistance to non-oxidizing acids like muriatic (hydrochloric) acid. However, instead of the sulfuric acid any other acid (hydrochloric acid, acetic acid, formic acid) is used, otherwise it remains with hydrogen peroxide. A popular classroom demonstration consists of filing notches into a new penny and soaking the penny in hydrochloric acid overnight. Copper is a not a noble metal per se like mercury, sliver, or gold, though it displays some of their properties in that copper will resist the degenerative reactions of muriatic acid in the absence of a catalyst. What happens to a modern penny when it is placed inside a bath of hydrochloric acid after the penny is scratched, exposing some of the zinc? Aug 12, 2019 · A copper penny can be dissolved in nitric acid but not in hydrochloric acid. . Hydrochloric acid dissolves the less active metals, such as zinc and magnesium, easily. Pennies in the United States consist of a zinc core that is electroplated with a thin coating of copper. Diesel? A student determines the mass of a penny to be 2. Nothing. It takes the HCl quite a bit of time to get through the copper, but once that has corroded a little, the zinc base dissolves like an Alka-Seltzer tablet in water, sending little copper flakes bouncing around until they finally dissolve. The percent of zinc and of copper can be calculated as well as the economic value of each. However, this is very unlikely because the pH of our stomach is between 1. Once this was done, I would be able to filter out my copper and then dissolve it in nitric acid to leave me with copper sulfate within a solution. When winning the copper salts, the procedure is similar. We put Nitric Acid through its paces, including dissolving coins. Dissolving the Guts Out of a Penny with Hydrochloric Acid - YouTube صورة #5 | دقة الصورة 480x640 Science chemistry redox reaction copper zinc | Fundamental Photographs - The Art of Science At this level of acidity, Coca Cola can dissolve the calcium in tooth enamel, chalk and limestone. Hydrochloric acid solution, 6 M, HCl, 20 mL Forceps or tongs Beaker, 100-mL Graduated cylinder, 50-mL Beaker of water One post-1982 penny File, triangular One pre-1982 penny Safety Precautions Hydrochloric acid is corrosive to eyes, skin, and other tissue and is highly toxic by ingestion or inhalation. Explanation: The main reason a solid copper penny can be dissolved in nitric acid but not in hydrochloric acid is due to their reactions with copper. Post-1982: purpose of this lab is to determine this. Unlike the previous experiment, the zinc will be all used up to obtain the copper. …look at the label. Equation: HC2H3O2 + NaCl ---> HCl + NaCH3O2. The reaction between the acid and the zinc is as follows: 2H+(aq)+Zn(s)→H2(g)+Zn2+(aq). Nitric Acid . How might this relate to your observations in Part 2 of this experiment? Oct 17, 2021 · The concentration of the acid affects its oxidizing capacity. Concentrated hydrochloric acid dissolves zinc Once the base metal is gone, filter, collect the gold, then dissolve in aqua regia. After 1 day, there were bubbles coming out from the notches that we carved in. (Here’s an interesting overview of the history of the penny. 20% hydrochloric acid even when heated made only slightest bubbling and no remarkable harm to nikcel surface. Because new pennies are made of zinc coated with copper, and hydrochloric acid dissolves zinc and not copper, the inside of the penny is dissolved by the acid, while the outer copper shell remains. If one adds NaCl to vinegar, you get HCl: $$\ce{CH3COOH +NaCl<=>CH3COONa +HCl}$$ Copper(II) chloride dissolves in the water. If a small scratch is made on the surface of a penny, it is possible to dissolve away the zinc core, leaving only the thin shell of copper. It's helpful to write all of the reduction half reactions that correspond to the potential Redox processes that will be oc… A copper penny can be dissolved in nitric acid but not in hydrochloric acid. Since pennies are copper plated, could some of the copper have dissolved into the molten zinc and been left behind after all the zinc was dissolved? For example, hydrochloric acid pairs hydrogen and chlorine as HCl. Home DIY rust removal methods include using Phosphoric Acid, Citric Acid, Vinegar, Hydrochloric Acid, Lemon with salt, potato, sand paper, steel wool, grinder, cream of tarter and electrolysis. However, this’s been proven to not happen. 9 torr. Hydrochloric acid reacts with zinc but not with copper to form hydrogen gas (H2) and zinc chloride (ZnCl2). Copper does not react with most acids. A penny with a scored edge allows the HCl to react with the int; The zinc within a copper-plated penny will dissolve in hydrochloric acid if the copper coating is filed down in several spots (so that the hydrochloric acid can get to the Mar 27, 2015 · Nitric acid is one of the few acids that dissolved copper (HCl and H2SO4 won't). Vinegar and other weak acids such as citrus juice dissolves this layer of copper oxide. Jan 4, 2018 · With a little bit of chemistry, you can determine what an unknown 1982 penny is made from. 76 V). We added hydrochloric acid solution. Using concentrated nitric acid, the copper in the penny begins to react imm The student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the HCl (the copper remains undissolved): Zn(s) + 2 HCl(aq)¡ H2( g) + ZnCl2(aq) The student collects the hydrogen produced over water at 25 °C. A copper penny can be dissolved in nitric acid but not in hydrochloric acid. Nov 11, 2022 · Therefore, my analytical plan started by dissolving the zinc, copper, and hydrochloric acid in my pennies. What causes the pennies to become dull? When the penny is placed in nitric acid: Zinc ions are produced since the reduction potential of zinc is also greater than zero (+0. When the acid dissolves in water, hydrogen splits off from the base and the solution becomes a powerful solvent. Stability in hydrochloric acid is not necessarily a measure of the value of a metal, but in this case, it is. Using reduction potentials given in the book, show why this is so. Identify which element is oxidized and which is reduced in the reaction for the dissolving of the zinc by the acid. You want to clean a $20 coin and risk replacing the septic system or sewer lines? Unless you are a chemical engineer, stay away from the acid. When gold is subjected to treatment with muriatic acid alone, nothing happens. What happens to the zinc in the penny when placed in nitric acid? Hydrochloric acid? Jul 1, 2007 · Hydrochloric acid (HCl), known in the hardware store as muriatic acid, is sold for cleaning concrete. In this activity, we will observe what happens to the copper when we expose the penny to common household solutions of vinegar, salt, and water. Jul 31, 2013 · Effect of cleaning coins with Concentrated Hydrochloric Acid. By using a file and some hydrochloric acid one can do a simple experiment that has redeeming educational value for only a few pennies in cost. How would the particle size of the zinc affect the rate of its dissolution? Rate of dissolution will reverse as particle size decreases since reaction rate is directly proportional to surface area of reactant Nov 17, 2013 · Hydrochloric acid (sometimes still known by its archaic name, "muriatic acid") is a much stronger acid than vinegar. 5°C. For example, copper does not react with dilute sulfuric acid (H 2 SO 4), but a similar reaction occurs in concentrated sulfuric acid: Cu + 2H 2 SO 4 → SO 2 + 2H 2 O + SO 4 2− + Cu 2+ Containing the Copper and Nitric Acid Reaction Sep 17, 2023 · Pennies minted after 1982 are of this copper/zinc composition. 00 grams of hydrochloric acid, will the acid dissolve all of the zinc? What mass of excess reactant remains once the reaction stops? Mar 13, 2018 · Muriatic acid, better known today as hydrochloric acid, is a simple, corrosive liquid with well-studied chemical properties. It is the Cu that gives the reddish color to the penny. Penny vs. What is an acid? An acid is a substance that is able to dissociate into hydrogen ions. 0 M HCl. What happens to the zinc in the penny when the coin is placed in nitric acid? Hydrochloric acid? Concentrated nitric acid is corrosive and oxidising - wear goggles or face shield. Pre-1982: contain 95% copper, 5% zinc. 5% copper coating. Nitrogen dioxide is toxic - the gas is bubbled through water in which it will dissolve and react. A student determines the mass of a penny to be 2. Zn (s) + 2 HCl (aq) → ZnCl 2 (aq) + H 2 (g) Apr 24, 2017 · Using the same principles, and a little patience, it is possible to dissolve a penny completely. 485 g and then makes several scratches in the copper coating (to expose the underlying zinc). With a high oxidative strength, nitric acid will completely dissolve copper, turning it green and then blue as the metal wears away in a matter of minutes. Using reduction potentials from the book, show why this is so. I either didn’t leave the penny in long enough, or I didn’t use enough acid. Copper is expensive and getting more so. 2. Wear gloves – CLEAPSS members should consult GL349. 7 ml of 50 percent acetic acid would be used. 5 and 3. This is a strong solution, and you should know what you're doing. Materials 3 pennies (NOTE: pennies dated before 1982 work best) Aug 26, 2019 · When cleaning a penny, the hydrochloric acid produced by the mixture of salt and vinegar dissolves a thin layer of copper on the penny. Aug 23, 2020 · Over time, copper pennies turn brown as the copper oxidizes with air. Other uses for salt and vinegar solution May 14, 2020 · VIDEO ANSWER: taps of this question. But it will also dissolve the zinc core of a penny, leaving a foil of copper roughly a thousandth of an inch thick bearing the original image of the coin. The dating is crucial because prior to this pennies were 95% copper and 5% zinc, but after 1982 pennies composed of 97. 5. cnndags xtgmx hiyuvw fvh jsjgql dsxs rsa mctkl rbqmp eogux iubva fnz raic ukm mxisa