# oxidation number of copper

## oxidation number of copper

Naturally occurring copper is a mixture of its two stable isotopes, 63Cu and 65Cu, with natural abundances of 69.2% and 30.8% respectively. Copper's element symbol --- Cu --- is derived from the Latin "cuprum," which translates to "metal of Cyprus," indicating where it was mined in ancient times. Which leaves Sn unknown, which we denote as x. Copper is essential in all plants and animals. Answer to: What is the oxidation state of copper before and after the reaction below? Copper is the oxidizing agent For online linking, please copy and paste one of the following: To cite this page in an academic document, please use the following MLA compliant citation: copper will kill sheep, which is why sheep and goat food are different, Actinium – Aluminum – Americium – Antimony – Argon – Arsenic – Astatine, Barium – Berkelium – Beryllium – Bismuth – Bohrium – Boron – Bromine, Cadmium – Calcium – Californium – Carbon – Cerium – Cesium – Chlorine – Chromium – Cobalt – Copernicium – Copper – Curium, Darmstadtium – Dubnium – Dysprosium – Einsteinium – Erbium – Europium, Fermium – Flerovium – Fluorine – Francium – Gadolinium – Gallium – Germanium – Gold, Hafnium – Hassium – Helium – Holmium – Hydrogen – Indium – Iodine – Iridium – Iron, Krypton – Lanthanum – Lawrencium – Lead – Lithium – Livermorium – Lutetium, Magnesium – Manganese – Meitnerium – Mendelevium – Mercury – Molybdenum – Moscovium, Neodymium – Neon – Neptunium – Nickel – Nihonium – Niobium – Nitrogen – Nobelium – Oganesson – Osmium – Oxygen, Palladium – Phosphorus – Platinum – Plutonium – Polonium – Potassium – Praseodymium – Promethium – Protactinium, Radium – Radon – Rhenium – Rhodium – Roentgenium – Rubidium – Ruthenium – Rutherfordium, Samarium – Scandium – Seaborgium – Selenium – Silicon – Silver – Sodium – Strontium – Sulfur, Tantalum – Technetium – Tellurium – Tennessine – Terbium – Thallium – Thorium – Thulium – Tin – Titanium – Tungsten, Uranium – Vanadium – Xenon – Ytterbium – Yttrium – Zinc – Zirconium, Copyright © 2020 chemicool.com I'm trying to write the formula for copper {II}Chloride and don't know which oxidation number i should use for copper. Beads made from native copper dating from the eighth millennium BC have been found i… Name the complex CrCl2(en)2 . It is also produced commercially by reduction of copper (II) solutions with sulfur dioxide. SO4 (sulphate) has a -2 charge. Follow • 2. Anonymous. Fewer bubbles generated on the copper surface after oxidation. (2), (3). Formula: CuO Hill system formula: Cu 1 O 1 CAS registry number: [1317-38-0] Formula weight: 79.545 Class: oxide Colour: black or brown-black Appearance: crytalline solid Melting point: l336°C (under 1 atmosphere oxygen) Boiling point: Density: 6310 kg m-3 On the grounds that Cu can show off different oxidation states: +1 and +2. Her juvenile nonfiction has appeared in such magazines as "Tech Directions," "Connect" and "Class Act." The basic reaction of copper and atmospheric oxygen, which converts copper to copper oxide, is: 2 Cu (s) + O 2 (g) --> 2 CuO (s) The copper to patina conversion is a multiple-step process, and it takes a long time to form copper carbonate. Oxygen has an oxidation of -2, so to balance it, copper needs to be +2. The oxidation state is therefore +2. Solution. How would u figure it out??? In its aggravates, the most widely recognized oxidation number of Cu is +2. We know that H in acids is at +1 state. In [ Cu ( NH3)4]SO4 , the oxidation number of NH3 is zero (0) because the ammonia molecule is a neutral molecule . Compare and contrast the closed circuit to the open circuit, please help Based on the visual representations above, define ALL three of the following words. If it were copper (I) sulfate the oxidation number would be 1+. Ammonia in this complex is not an ion, it is a neutral structure covalently bound to the copper atom; thus having a net oxidation number of 0. Lol, what I mean is, they give you copper(II) chloride. Copper has two oxidation numbers that are common. This result is in accordance with the activity series. It is one of the principal oxides of copper, the other being CuO or cupric oxide.This red-coloured solid is a component of some antifouling paints. Oxidation of copper under thick (10–30 mm) layers of Bi 2 O 3 was analysed in a number of studies. Effects of Oxidation on Copper. It has been known since ancient times. What is the oxidation number of atom X in H 2 XO 3-? Identify the oxidation number of each element in the reaction. It is also used in plumbing and in cookware and cooking utensils. The oxidation number of copper decreases from +2 to 0. Copper oxide in Fehling’s solution is widely used in tests for the presence of monosaccharides (simple sugars). Under certain conditions, these copper items can be affected by oxidation. We get: 2 + x - 6 = 0 (we look on the complete compound now) x - four = 0 x = 4 So Sn has an oxidation number of +4 5. 1 Introduction. The oxidation number is a number that indicates the degree of ionization. Except in metal hydrides, which this is not, Hydrogen always has an oxidation state of +1. To verify this, we ought to think somewhat. It can be added to vitamins to get copper into the body. The copper (II) oxide provides the oxygen necessary for the oxidation reaction, with a concomitant reduction of the copper (II) oxide to copper (I) oxide or elemental copper. Write the reaction for this redox process, and identify what is oxidized and what is reduced in the process. The only thing left is to account for the overall charge of the complex is copper atom; indicating that it has an oxidation number of +2. Cop­per is an el­e­ment that be­longs to the group of met­als and holds 29th place on Mendeleev’s pe­ri­od­ic ta­ble. What is the oxidation number of the copper in copper (II) sulfate? Copper-Catalyzed Hydroquinone Oxidation and Associated Redox Cycling of Copper under Conditions Typical of Natural Saline Waters. Environmental Science & Technology 2013 , 47 (15) , 8355-8364. Safety. Copper has been used by humans for as many as ten thousand years. Pure copper(I) iodide is white, but samples are often tan or even, when found in nature as rare mineral marshite, reddish brown, but such color is due to the presence of impurities. Favorite Answer. What is the oxidation number of atom X in H 2 XO 3-? 3- Every gray copper represent 1/2 oxidation process. The patina gives the Statue of Liberty its characteristic appearance, but the oxidation of copper can also cause undesirable effects under some circumstances. When iron rusts, or oxidizes, it produces that characteristic red outer layer. Growing copper sulfate crystals is cool – chemicool in fact. Copper(II) oxide is toxic when eaten. When metals are placed in a high temperature environment, oxidation of such metals occurs when oxide film or scale begins to form on their surfaces. Copper(II) oxide is used to color ceramics. The oxidation behavior of copper has therefore received considerable interest for a very long time 1-3.At temperatures above 600 °C, it is believed that the oxidation is controlled by the lattice diffusion of copper ions through a Cu 2 O layer 4-6. The compound can appear either yellow or red, depending on the size of the particles. Copper metal is extracted from an acidic solution of copper nitrate. Most straightforwardly, it arises via the oxidation of copper metal: 4 Cu + O 2 → 2 Cu 2 O Additives such as water and acids affect the rate of this process as well as the further oxidation to copper (II) oxides. Oxygen therefore, is the oxidising agent and copper is the reducing agent. This layer of oxidation doesn't securely stick to the surface of the iron. It is malleable, ductile, and an excellent conductor of heat and electricity – only silver has a higher electrical conductivity than copper. Finally, the resulting crude copper is purified by electrolysis involving plating onto pure copper cathodes. Solution for The oxidation of copper(1) oxide, Cu,O(s), to copper(II) oxide, CuO(s), is an exothermic process. In addition, care must be taken not to overheat the copper during the soldering process, as excess heat produces copper oxidation, and the solder won't adhere to it. The copper (Cu) is present in neutral state. Oxidation states simplify the whole process of working out what is being oxidised and what is being reduced in redox reactions. I looked at the periodic table and it says copper has a +1 and +2 charge , which one do i use? When the copper cooking surface comes into contact with acidic food (i.e. I'm trying to write the formula for copper {II}Chloride and don't know which oxidation number i should use for copper. Mg is in the equal group as Ca. Oxygen is reduced because the oxidation number decreases, and copper is oxidised. Copper Hydroxide,has a structural formula of Cu(OH)2,and as the OH ion always shows -1 state,Copper exhibits an oxidation state of +2,to make the sum of oxidation numbers of constituent atoms,Zero. Educ., 1933, 10 (4), p227. The oxidation number of copper decreases from $$+2$$ to $$0$$. However, copper oxidation produces harmful effects in copper cookware. What are the oxidation numbers for CuSO4? As it always is in ammonia. Copper electrical wire and copper pipes must be cleaned with acid-free cleaners before soldering takes place. vinegar, ascetic acid). In fact, copper has been used by humans for about 10,000 years. The copper-bearing solution is collected and pumped to the extraction plant where it is purified. Copper sulfate is used as a fungicide and as an algicide in rivers, lakes and ponds. The oxidation number of nickel is +2. Attraction B. Repulsion C. Rotation Write the balanced reaction. Copper is neither oxidized nor reduced. It progresses through a number of steps that combine an organic solvent or sulfuric acid to the solution until the copper concentration is high enough for effective electro-plating. 10H 2 O? Therefore, the oxidation number of copper (Cu) is 0. Name the salt K4[Pt(CO3)2F2] given that the carbonate ion acts as a monodentate ligand in the complex. A. RE: What is the oxidation number of Copper? Element % Cu: 33.37: I: 66.63: Isotope pattern for CuI . Crucibles and slags found in Europe suggest that smelting of copper (producing the metal from its ores) took place in the fifth millennium BC. It is 2+. In a reaction, the oxidation number of copper goes from +1 to +2. Copper and air Copper statues, such as the Statue of Liberty, begin to appear green after they have been exposed to air. The Copper Age sits between the Neolithic (Stone) and Bronze Ages. Copper, Cu(s), has an oxidation state of zero (0). Which species is being oxidized in the reaction. Copper is a versatile metal used in thousands of everyday products. Therefore the compound would be K2B2O4 with B having a +three oxidation number. Copper is then obtained by smelting and leaching. Methods of copper oxidation How it reacts with air. Saul S. Hauben, The derivations of the names of the elements, J. Chem. CuFeS2 or copper pyrite is a lattice level combination of Cu(I) and Fe(III) sulphides. The word copper is derived from the Latin word ‘cuprum’ meaning ‘metal of Cyprus’ because the Mediterranean island of Cyprus was an ancient source of mined copper. (adsbygoogle = window.adsbygoogle || []).push({}); A nugget of natural, native copper with imbedded copper minerals. Share Tweet Send Cop­per ox­i­da­tion is a nat­u­ral process. She has also written articles for Katy Magazine Online. Joan Whetzel has been writing professionally since 1998. The mechanism of oxidation depends on the nature of the scales that is, whether the oxide is solid, liquid, or gaseous. Under higher heat flux, the vapor cover area decreased, which was a result of the reduction in NSD after oxidation. Zn 2+ (aq) + 2Cr 2+ (aq) →Zn(s) + 2Cr 3+ (aq) 2 Answers. Its discoverer and discovery date are unknown. Copper is the reducing agent. X-ray absorption edge determination of the oxidation state and coordination number of copper. Solution for What is the oxidation number of copper in the complex ion [CuCl4]2-? Copper oxidation, on the other hand, prevents further oxygen exposure and corrosion by solidly adhering to the metal's surface. Denoting Mn's state as x, we get: 2 +x - eight = 0 x - 6 = 0 x = 6 So Mn has an oxidation quantity of +6 Hope this helps Hydrogen is +1; Nitrogen is -3; Copper is +2 -----PS: To balance the equations, just add water (and hydroxide). The oxidation number of Copper will be +2. Answered by | 4th Apr, 2014, 04:38: PM Related Videos In this redox process, copper metal reacts with oxygen to form solid copper oxide, which forms the green coating. Geometry of copper: Prototypical structure: ZnS (sphalerite, zinc blende) Element analysis. Oxidation occurs as a result of copper's exposure to air, though water --- especially salt water --- heat and acidic compounds can also induce corrosion. This is because all the oxidation numbers need to equal to zero, since copper (II) oxide does not have a charge. When it's with another element, ( as in copper(II) chloride), the oxidation number changes. Please explain in detail. Copyright 2020 Leaf Group Ltd. / Leaf Group Media, All Rights Reserved. It oxidizes readily to form a distinctive coating known as patina. The problem in this case is that the compound contains two elements (the copper and the sulfur) with variable oxidation states. In its aggravates, the most widely recognized oxidation number of Cu is +2. Structure is similar to that of ZnS (sphalerite form) in which Cu+ and Fe3+ ions alternately substitute for Zn2+. Hope this helps~ Well, copper metal has an oxidation number of ZERO.... And oxidation number is defined here. Subjects: Oxidation/Reduction, Net ionic equations Description: When a ball of aluminum foil is placed in a copper solution with chloride ions, the copper ions are reduced to copper metal and a coating of copper is seen on the surface of the aluminum. Kluwer Academic/Plenum. Copper, Cu(s), has an oxidation state of zero (0). Douglass Whitfield Bailey, Balkan Prehistory: Exclusion, Incorporation and Identity, 2000, p210. The (II) is a dead give away to the oxidation number. vinegar, wine), it produces a toxic verdigris, which is poisonous if ingested. Although only small amounts of native copper can be found, there was enough of it for our ancestors to discover the metal and begin using it. Zn 2+ (aq) + 2Cr 2+ (aq) →Zn(s) + 2Cr 3+ (aq) Expert Answer 100% (3 ratings) Previous question Next question Get more help from Chegg. The oxidation number of platinum is +2. Iron is above copper in the series, so will be more likely to form $$\ce{Fe^{2+}}$$ while converting the $$\ce{Cu^{2+}}$$ to metallic copper $$\left( \ce{Cu^0} \right)$$. If water and air are present, copper will slowly corrode to form the carbonate verdigris often seen on roofs and statues. Relevance. This result is in accordance with the activity series. we know there is sulphuric acid (H2SO4) hydrogen ions each have a +1 charge so since there are 2. 5.0 (104) Ph.D. University Professor with 10+ years Tutoring Experience. This is copper (I) chloride. One positive effect of copper oxidation includes the formation of a protective outer layer that prevents further corrosion. Thanks. The oxidation number of copper decreases from $$+2$$ to $$0$$. It can be eaten in very small amounts, such as in vitamins. 2 Cu,O(s) + 0,(g) → 4CUO(s) The change in… Copper mining and smelting were commonplace by 4500 BC in the Balkans – Bulgaria, Greece, Serbia and Turkey. Copper is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29. Less basic is +1. Cooking acidic food in copper pots can cause toxicity. Well, the oxidation number of an element is always zero. The chemical element copper is classed as a transition metal. Copper(I) oxide is found as the reddish mineral cuprite. Chemistry Dictionary | Birth of the Elements | Tools | Periodic Table | Citing Chemicool | About | Privacy | Contact. Explaining what oxidation states (oxidation numbers) are. 2Al + 3CuSO4 = 3Cu + Al2(SO4)3. Of all the metals, copper is the one most likely to be found in its native state, often released by the chemical reaction of its ores. Copper(II) ions gain electrons and gain of electrons is reduction. Verdigris (corroded copper) on rooftop decorations. The oxidation rate of both the pure copper as well as the nickel-plated copper was approximately parabolic in the temperature range studied. Application to the type 3 site in Rhus vernicifera laccase and its reaction with oxygen The oxidation number of copper in copper iodide is 1. However, for the purposes of this introduction, it would be helpful if you knew about: oxidation and reduction in terms of electron transfer. In this case, it's +2 because the problem said so. Consider sulfuric acid: H2SO4. Report 1 Expert Answer Best Newest Oldest. -2 B. Refining Sulfide Ores. What is the oxidation number of atom Y in YSO 3. Less basic is +1. Oxidized copper is a specific type of corrosion that is produced during a three-step process where copper oxidizes to copper oxide, then to cuprous or cupric sulfide, and finally to copper carbonate. The Copper Age was followed by the Bronze Age, when people learned that by adding tin to copper, a harder metal that is also more easily cast was formed. Oxidation adds a verdigris color (blue-green) to copper or copper carbonates like brass or bronze. What is the oxidation number (charge) of Copper in CuMnO4 ? Copper is a reddish orange, soft metal that takes on a bright metallic luster. On the other hand the oxidation number of SO4 ion is –2 . Commercially important alloys such as brass and bronze are made with copper and other metals. It took place at different times in different cultures, when people began using copper tools alongside stone tools. ﻿ O x i d a t i o n n u m b e r o f C u (N O 3 ) 2 = O x i d a t i o n n u m b e r o f C u + 2 × O x i d a t i o n n u m b e r … Unfortunately, it isn't always possible to work out oxidation states by a simple use of the rules above. The oxidation number of copper (Cu) in ﻿ C u (N O 3 ) 2 ﻿ is calculated as shown below. The oxidation of copper is an important issue both for academic research and industrial applications. Sarunas Milisauskas, European Prehistory., 2003, p207. Although only small amounts of native copper can be found, there was enough of it for our ancestors to discover the metal and begin using it. As a result of its excellent electrical conductivity, copper’s most common use is in electrical equipment such as wiring and motors. So we now have SO4 having a -2 cost. I looked at the periodic table and it says copper has a +1 and +2 charge , which one do i use? It is common for samples of iodide-containing compounds to become discolored due to the facile aerobic oxidation of the iodide anion to molecular iodine. Cop­per, like all oth­er met­als, is ca­pa­ble of ox­i­da­tion, form­ing sta­ble bonds in the forms of ox­ides and salts. Recognize the formula as being copper (II) sulfate (the (II) designation indicates that copper is in a +2 oxidation state, as discussed below). Copper oxidation, on the other hand, prevents further oxygen exposure and corrosion by solidly adhering to the metal's surface. In addition, copper roofing, gutters and rain spouts stand up to weathering, since the corrosion process is so slow. +4 C. +2 D. 0 The other is Coupric, which has an oxidation number of +2. It can react with many toxic chemicals to oxidize them, so they are not toxic any more. (Copper Sulfate)? What is the oxidation number of atom Y in YSO 3. 10H 2 O? It oxidizes readily to form a distinctive coating known as patina. Most copper ore is mined or extracted as copper sulfides. (1). About this tutor › About this tutor › The (II) is a dead give away to the oxidation number. Copper(II) oxide loses oxygen and loss of oxygen is reduction. Answer Save. The table shows element percentages for CuI (copper iodide). One positive effect of copper oxidation includes the formation of a protective outer layer that prevents further corrosion. RE: What is the oxidation number of Copper? Tutor. as the uncombined metal), and is also found in many minerals such as the oxide; cuprite (Cu2O), the carbonates; malachite (Cu2CO3(OH)2)and azurite (Cu2(CO3)2(OH)2) and the sulfides; chalcopyrite (CuFeS2) and bornite (Cu5FeS4). 1 decade ago. It can also be added to clothing to kill germs. Beads made from native copper dating from the eighth millennium BC have been found in Turkey. Copper cookware should be lined to prevent ingestion of toxic verdigris (compounds formed when copper corrodes). The oxidation number of each copper atom changes from 0 to + 2 because 2 electrons were lost, and the oxidation number of each oxygen atom changes from 0 to 2 because 2 electrons were gained. You can recognise a redox … She was part of the production team that produced the documentary "Fuel for Thought" on Houston PBS. Not available. In the course of the reaction, the oxidation number of Fe increases from zero to +2. The number of bubbles generated on the surface was calculated by a python code and it showed an inverse relationship with CHF, which was explained by a model. The first, is Couprous with an oxidation number of +1. Copper,in nature,mainly exhibits two oxidation states.It can either have a +1 state, or a +2 state, depending on several factors. By: J.R. S. answered • 05/07/20. Why? electron-half-equations. Because it corrodes slowly, copper is used in roofing, guttering, and as rainspouts on buildings. Copper has a +1 or +2 charge. 4 Al (s) + 3 O 2 (g) 2 Al 2 O 3 (s) These minerals impart the characteristic bluish-green color to oxidized copper metal and form the … Iron is above copper in the series, so will be more likely to form $$\ce{Fe^{2+}}$$ while converting the $$\ce{Cu^{2+}}$$ to metallic copper $$\left( \ce{Cu^0} \right)$$. To balance that of the hydrogen, this leaves the nitrogen atoms with an oxidation number of -3. Oxide Ore. Source: Copper is occasionally found native (i.e. oxidation number of copper is +2. Copper chloride gave a white precipitate and then it dissolved, forming a colorless solution, when more thiourea was added. What is the oxidation number of copper in CuSO 4? Which species is being oxidized in the reaction. Copper is being reduced. so CuSO4, the Cu has to have +2 charge to have … We'll assume you're ok with this, but you can opt-out if you wish. Routledge. What is the oxidation state of copper in CuSO 4? Copper has two oxidation numbers that are common. Copper has been used by humans for as many as ten thousand years. The oxidation number of copper is +2. The element symbol Cu also comes from ‘cuprum.’ (4). (Keywords: temperature, oxidation kinetics, copper, alloys, oxide films) INTRODUCTION . Add comment More. Of all the metals, copper is the one most likely to be found in its native state, often released by the chemical reaction of its ores. Copper is a versatile metal used in thousands of everyday products. Copper is flexible and pliable, and it conducts heat and electricity well, making it useful for electrical wiring. Now, let the oxidation number of Cu is ‘X’ . Again this happened at different times in different locations in the world. Abundance earth’s crust: 60 parts per million by weight, 19 parts per million by moles, Abundance solar system: 700 parts per billion by weight, 10 parts per billion by moles. She has written juvenile nonfiction, movie and television scripts and adult nonfiction. Copper compounds burn with a distinctive green flame. 2, 3, 5, 52 It was found that 0.2–1 mm-thick copper plates are oxidized super-fast (within 5–10 s) upon Bi 2 O 3 melting (820 °C), and simultaneously Bi 2 O 3 is reduced to metallic bismuth. This website uses cookies to improve your experience. Today, copper appears in products from cookware, electrical wires and plumbing to jewelry and sculpture. or. It flakes off, weakening the metal and leaving it vulnerable to further rusting and structural decay. Isotopes: Copper has 24 isotopes whose half-lives are known, with mass numbers 57 to 80. Excess copper is, however, toxic. Once another silver ion reacts with copper of oxidation state +1 ending with oxidation state +2, that Cu(II) ion dissociates into solution. If iron is oxidized to Fe2+ by a copper(II) sulfate solution, and 0.770 grams of iron and 13.8 mL of 0.545M copper(II) sulfate react to form as much product as possible, how many millimoles (mmol) of the non-limiting reactant will remain unused at the end of the reaction? Synthesis. Copper's distinctive red-orange color and bright luster makes it appealing for decorative metalwork, jewelry and cookware. The first, is Couprous with an oxidation number of +1. Sulphate ion SO 4 2-carries charge of -2, as NH 3 carries no charge, therefore charge on copper is +2, i.e. Solid zinc and aqueous copper (II) nitrate react to form solid copper and aqueous zinc nitrate. In another embodiment of the invention, the process steps are conducted in a vertical tube reactor system, wherein the necessary pressure is achieved by hydrostatic head pressure inherent in the system. Select one: A. Show more, including: Heats, Energies, Oxidation, Reactions. This is especially true when contact with anything acidic in nature occurs (e.g. What is the oxidation number of copper in CuSO 4? This protection can be seen on copper roofs and gutter work as well as on outdoor sculptures and statuary, namely the Statue of Liberty. The oxidation number of chromium is +2 Name the salt [Ni(H2O)3(CO)]SO4 . The other is Coupric, which has an oxidation number of +2. Example $$\PageIndex{3}$$: Copper. The patina gives the Statue of Liberty its characteristic appearance, but the oxidation of copper can also cause undesirable effects under some circumstances. Copper surfaces exposed to air gradually tarnish to a dull, brownish color. The (II) means it's a +2 charge. Solid state structure. Amount of non-limiting reactant remaining unused = mmol When copper atom reacts with a silver ion, it turns gray as an indication of a change in oxidation state from 0 to +1. The thicknesses of the oxidized layers for copper and nickel-plated copper are given by the following two equations, respectively Cu :t(mm)=50,000× exp −1.97− 18,000 T(K) × Years Ni plated Cu :t(mm)=23,000× exp −7.3− 17,300 T(K) … To balance that of the hydrogen, this leaves the nitrogen atoms with an oxidation number of -3. So it too has +2 as its state. 3. Copper(I) oxide or cuprous oxide is the inorganic compound with the formula Cu 2 O. Gun metals and American coins are copper alloys. To form an electrically neutral compound, the copper must be present as a Cu 2+ ion. Study the diagram above. Oxidation also hinders the electrical conductivity of copper wire. It is also used to make thermite. What can we say about this reaction: Group of answer choices.