Citric acid, HOOCCH2C(OH)(COOH)CH2COOH(s),(IRRITANT) see CLEAPSSHazcard HC036C. Now add about 10 cm 3 of sodium hydroxide solution and shake the mixture. So generally speaking, energy is released when a bond is formed, while energy is required (energy is absorbed) to break a bond. Direct link to PHILOSOPHERAMNA's post could this be explained i, Posted 2 years ago. Since nitric acid has both acidic and basic properties, it can undergo an autoprotolysis reaction, similar to the self-ionization of water: Nitric acid reacts with most metals, but the details depend on the concentration of the acid and the nature of the metal. The reactions in the Copper Cycle were exothermic and endothermic. You're on the right track. Heat changes - EXOTHERMIC and ENDOTHERMIC. More recently, electrochemical means have been developed to produce anhydrous acid from concentrated nitric acid feedstock. Ammonium nitrate, NH4NO3(s)(OXIDISING) see CLEAPSSHazcard HC008. Direct link to Anjali Joseph's post idk i am assuming the fri, Posted 2 months ago. Add 4 small (not heaped) spatula measures of citric acid. whether exothermic . Same concept, different interpretation. Fuming nitric acid is concentrated nitric acid that contains dissolved nitrogen dioxide.] Please help my confusion! [19], Nitric acid has been used in various forms as the oxidizer in liquid-fueled rockets. Some reactions give out heat and others take in heat. 556 0 obj
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2.8.1 define the terms exothermic and endothermic and understand that chemical reactions are usually accompanied by heat changes; Spot the entropy errors worksheet | 1618 years, Gold coins on a microscale | 1416 years, Practical potions microscale | 1114 years, Antibacterial properties of the halogens | 1418 years, Typical expanded polystyrene cups fit snugly into 250 cm. Once all the magnesium ribbon has reacted, discard the mixture (in the sink with plenty of water). Citric acid, HOOCCH2C(OH)(COOH)CH2COOH(s),(IRRITANT) see CLEAPSSHazcard HC036c. The color produced is a grey-gold very much like very old wax- or oil-finished wood (wood finishing). Metal + Acid = Salt + Hydrogen . The endothermic separation of the ions will dictate the overall reaction, since the exothermic hydration of the ions will gfive off less energy. Nitric acid (HNO3) and potassium hydroxide (KOH) combine in a neutralization reaction to form water and a salt. However, when the separated ions become hydrated in the solution, an exothermic . Is acetate a weak base due to its resonance structure? (Halides have colored precipitate.) Production of nitric acid is via the Ostwald process, named after German chemist Wilhelm Ostwald. Sample Problem: The neutralization of a solution of potassium hydroxide by nitric acid is an example of an exothermic reaction. If the initial dissolution process is exothermic (H < 0), then the dilution process is also exothermic. I'm not sure the changing states part of this article is correct. Rinse out and dry the polystyrene cup. [38] This process is based upon the oxidation of atmospheric nitrogen by atmospheric oxygen to nitric oxide with a very high temperature electric arc. Find out whether the reaction: In this activity students meet two exothermic reactions (1and 2) and two endothermic reactions (2and 4). Access to the following solutions (all at approx 0.4 M concentration): The reactions and types of reaction involved are: Try this student activity ontemperature changes in exothermic and endothermic reactions,featuring teacher notes and a downloadable worksheet. South Korea Middle Class,
Nuffield Foundation and the Royal Society of Chemistry, Follow this guide to introduce and develop your students literacy skills in science. 3H2O. Explanation: And here we got a strong base, potassium hydroxide, and a strong acid, in aqueous solution. NFPA National Fire Protection Association; Fire Protection Guide to Hazardous Materials. with a fat or oil to form soap. Use this practical to investigate how solutions of the halogens inhibit the growth of bacteria and which is most effective, The physics of restoration and conservation, RSC Yusuf Hamied Inspirational Science Programme, How to prepare for the Chemistry Olympiad. Cast iron cathodes were sunk into the peat surrounding it. Next is sodium hydroxide. %%EOF
Do . [Note: Often used in an aqueous solution. Being a powerful oxidizing acid, nitric acid reacts with many organic materials, and the reactions may be explosive. This collection of over 200 practical activities demonstrates a wide range of chemical concepts and processes. 22. Stated differently, less energy is released from making acetate ion from acetic acid than from making chloride ion from hydrochloric acid (or water from hydronium ion). During the course of the reaction, there exists an intermediate stage, where chemical bonds are partially broken and partially formed. Such reactions are called reversible reactions and are represented: A + B C + D. 4.7.4 The rate and extent of chemical change. It is a highly corrosive mineral acid. strong acid and strong base gives a NEUTRAL solution. hV[o:+~lNEZaO+!Rh!AIzTq%,[3u`#:[ QArRAF*P""PPCLsK
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+G}QNc. Could someone further explain this difference? Use this practical to investigate how solutions of the halogens inhibit the growth of bacteria and which is most effective, The physics of restoration and conservation, RSC Yusuf Hamied Inspirational Science Programme, How to prepare for the Chemistry Olympiad, class practical and teacher demonstration, Read our standard health and safety guidance, temperature changes in exothermic and endothermic reactions. Work out the temperature change and decide if the reaction is exothermic or endothermic. Alternatively, the reaction of equal moles of any nitrate salt such as sodium nitrate with sulfuric acid (H2SO4), and distilling this mixture at nitric acid's boiling point of 83C. Nuffield Foundation and the Royal Society of Chemistry, Steer students away from ionic bonding misconceptions with these ideas for your classroom, Use these ideas and activities to help your chemistry students master this challenging topic, Develop your learners metacognitive skills using thermodynamics questions and calculations, Practical experiment where learners produce gold coins by electroplating a copper coin with zinc, includes follow-up worksheet. When I teach phase changes, I describe the intermolecular forces as being "bonds of arrangement" -that are why solids keep their shape and "bonds of attraction" - that are why liquids (like water) form cohesive drops and have a definite volume. In my science class, I was taught that when heat is absorbed, something gets hotter. 'exothermic' in a sentence. Posted 7 years ago. How do you get out of a corner when plotting yourself into a corner, How to tell which packages are held back due to phased updates, A limit involving the quotient of two sums. Unit 2: Further Chemical Reactions, Rates and Equilibrium, Calculations and Organic Chemistry, Unit AS 2: Further Physical and inorganic Chemistry and an Introdution to Organic Chemistry. Isn't it supposed to release heat to cook an egg or anything else? This is a useful class experiment to introduce energy changes in chemical reactions, suitable for 1114 and 1416 year olds. Normally, the nitric oxide produced by the reaction is reoxidized by the oxygen in air to produce additional nitrogen dioxide. Nitric acid plays a key role in PUREX and other nuclear fuel reprocessing methods, where it can dissolve many different actinides. 5. The anhydrous salt can be regenerated by heating in a hot oven. Potassium Carbonate And Hydrochloric Acid Reaction Exothermic Potassium Carbonate And Hydrochloric Acid Reaction Exothermic Chemical Reactions for the Chemistry Olympiad Flashcards. Short Term Electricity Plans Texas, In this video we'll balance the equation Potassium hydroxide + Nitric Acid and provide the correct coefficients for each compound.To balance KOH + HNO3 = KNO3 + H2O you'll need to be sure to count all of atoms on each side of the chemical equation.Once you know how many of each type of atom you can only change the coefficients (the numbers in front of atoms or compounds) to balance the equation for Potassium hydroxide + Nitric Acid.Important tips for balancing chemical equations:Only change the numbers in front of compounds (the coefficients).Never change the numbers after atoms (the subscripts).The number of each atom on both sides of the equation must be the same for the equation to be balanced.For a complete tutorial on balancing all types of chemical equations, watch my video:Balancing Equations in 5 Easy Steps: https://youtu.be/zmdxMlb88FsMore Practice Balancing: https://youtu.be/Qci7hiBy7EQDrawing/writing done in InkScape. [25] It is also used to clean glass before silvering when making silver mirrors. Practical Chemistry activities accompanyPractical Physics andPractical Biology. 4.5.1.1 Energy transfer during exothermic and endothermic reactions. ][clarification needed]). endstream
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What do you observe? ISO 14104 is one of the standards detailing this well known procedure. The teacher may prefer to keep the magnesium powder under their immediate control and to dispense on an individual basis. Put 10 drops of potassium chromate(VI) solution in a test tube. Washing is continued for at least 1015 minutes to cool the tissue surrounding the acid burn and to prevent secondary damage. MathJax reference. It furnishes lesser $\ce{H3O+}$ in solution compared to a typical strong acid. [38][39] The nitric oxide was cooled and oxidized by the remaining atmospheric oxygen to nitrogen dioxide, and this was subsequently absorbed in water in a series of packed column or plate column absorption towers to produce dilute nitric acid. Why are trials on "Law & Order" in the New York Supreme Court? Solids have the largest amount and strongest intermolecular bonds (which is why particle movement is so limited). Distinguish between endothermic and exothermic reactions on the basis of the temperature change of the surroundings. HNO. Its ability to dissolve certain metals selectively or be a solvent for many metal salts makes it useful in gold parting processes. The slideshow describes an exothermic reaction between dilute sodium hydroxide and hydrochloric acid and an endothermic reaction between sodium carbonate and ethanoic acid. Neutralising nitric acid always makes "nitrate" salts. For example, one source which gives the enthalpy change of neutralization of sodium hydroxide solution with HCl as -57.9 kJ mol-1: Reaction Start temp ( C) End temp (C) Change in temp (C) Endo or exo? Are these exothermic or endothermic reactions Yahoo. The experiment is also part of the Royal Society of Chemistrys Continuing Professional Development course:Chemistry for non-specialists. The process occurring involves the equilibrium between chromate(VI), dichromate(VI) and hydrogen ions: 2CrO42(aq) (yellow) + 2H+(aq) Cr2O72(aq) (orange) + H2O(l). Consider chemical reactions in terms of energy, using the terms exothermic, endothermic and activation energy, and use simple energy profile diagrams to illustrate energy changes. Thus, for an exothermic process, the surroundings gain energy whereas the chemicals lose an equivalent amount. Professional Development Workshops For Interns, A gas evolution reaction is a chemical process that produces a gas, such as oxygen or carbon dioxide. Balancing Strategies: This is a neutralization reaction with the nitric acid and potassium hydroxide combine to form a salt (KNO2) and water. In electrochemistry, nitric acid is used as a chemical doping agent for organic semiconductors, and in purification processes for raw carbon nanotubes. To log in and use all the features of Khan Academy, please enable JavaScript in your browser. In the laboratory, further concentration involves distillation with either sulfuric acid or magnesium nitrate, which serve as dehydrating agents. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. a) nitric acid and potassium carbonate b) sodium bromide and lead nitrate c) acetic acid and calcium hydroxide d) calcium nitrate and sodium sulfate e) ammonium chloride and lithium hydroxide a) Molecular: 2HNO3 (aq) + K2CO3 (s) -> 2KNO3 (aq) + CO2 (g) + H2O (l) Ionic: 2H+ (aq) + 2NO3- (aq) + K2CO3 (s) -> 2K+ (aq) + 2NO3- (aq) + Co2 (g) + H2O (l) The red fuming nitric acid obtained may be converted to the white nitric acid. The solutions could be provided in small (100 cm3) labelled conical flasks or beakers. Sam asks, Teacher, why did my flask turn cold after adding the salt to water, while Julies flask turned hot?, The teacher replies: Thats because you were given two different salts. Among widely recognizable exothermic reactions is the combustion of fuels (such as the reaction of methane with oxygen mentioned previously). Solved Sample Problem: The neutralization of a solution of Professional Development Workshops For Interns. Carry out the following reactions. Reaction with non-metallic elements, with the exceptions of nitrogen, oxygen, noble gases, silicon, and halogens other than iodine, usually oxidizes them to their highest oxidation states as acids with the formation of nitrogen dioxide for concentrated acid and nitric oxide for dilute acid. The given reaction is exothermic and really fast, and therefore the first reaction will be the correct choice for instant and vigor reaction. In exothermic reactions the temperature goes up, in endothermic reactions the temperature goes down. If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked. HFKvMc`; I
Copyright 2020 TouchPoint all rights reserved. To a large extent, this page simply brings together information from a number of other pages . 1. Stir with the thermometer and record the maximum or minimum temperature reached. Many explosives, such as TNT, are prepared this way: Either concentrated sulfuric acid or oleum absorbs the excess water. To understand Enthalpies of Solution and be able to use them to calculate the Heat absorbed or emitted when making solutions. They observe the resulting colour changes, before reversing the reaction using aqueous sodium hydroxide. With more concentrated nitric acid, nitrogen dioxide is produced directly in a reaction with 1:4 stoichiometry: Upon reaction with nitric acid, most metals give the corresponding nitrates. If we have equimolar solutions of HCl and CH3COOH both of which are monoprotic, won't we still need an equal number of moles of NaOH to neutralise both? Some precious metals, such as pure gold and platinum-group metals do not react with nitric acid, though pure gold does react with aqua regia, a mixture of concentrated nitric acid and hydrochloric acid. Concentrated nitric acid stains human skin yellow due to its reaction with the keratin. Wear eye protection (goggles) throughout. [citation needed], Nitric acid can be used as a spot test for alkaloids like LSD, giving a variety of colours depending on the alkaloid.[27]. Consider the reaction mixturesalt plus wateras the, In Sams case, when ammonium nitrate was dissolved in water, the. previous next Examples of endothermic processes include the melting of ice and the depressurization of a pressurized can. Water will cause an exothermic reaction with nitric acid, causing the evolution of large amounts of NO 2; however, high-pressure water fog will contain the fumes. Nitration of organic compounds with nitric acid is the primary method of synthesis of many common explosives, such as nitroglycerin and trinitrotoluene (TNT). 605 0 obj
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Put a spatula measure of white, anhydrous copper(II) sulfate powder into a test tube. Most commercially available nitric acid has a concentration of 68% in water. Add nitric acid and silver nitrate solution. Information about your use of this website will be shared with Google and other third parties. In this case, heat is released during the reaction, elevating the temperature of the reaction mixture, and thus Julies reaction flask feels hot. In 1776 Antoine Lavoisier cited Joseph Priestley's work to point out that it can be converted from nitric oxide (which he calls "nitrous air"), "combined with an approximately equal volume of the purest part of common air, and with a considerable quantity of water. Sodium hydroxide solution, NaOH(aq)(CORROSIVE) see CLEAPSSHazcard HC091aand CLEAPSSRecipe Book RB085. A solution of nitric acid, water and alcohol, nital, is used for etching metals to reveal the microstructure. Students can be asked to draw simple energy diagrams for each type of reaction. CAS No. This reaction is known as the xanthoproteic reaction. In other words, the products are less stable than the reactants. This means the total enthalpy of reaction, H has a value of -2.535 kJ because the heat is being released from the reaction. Decide whether various reactions are exothermic or endothermic by measuring temperature change in this class practical. Chemistry. The energy required to reach this transition state is called activation energy. Hiba Bukhari Mother Name, Classify substances as elements, compounds, mixtures, metals, non-metals, solids, liquids, gases and solutions. Nitric oxide is then reacted with oxygen in air to form nitrogen dioxide. The formation of slaked lime (calcium hydroxide, Ca (OH) 2) when water is added to lime (CaO) is exothermic. Q8. The other main applications are for the production of explosives, nylon precursors, and specialty organic compounds.[19]. [UZ-\eR'E]}Z% k'1M^J!;;JbU7B0_(>\z[/dlq]] >^:2zTDe&SzQ0n/Jby*s'.. yzv+,=>+l\ E
Jbc.X6ZcsUAo4Am?FG4%Y6c{7R*.+mo4pg7I7l1CCgK8Zm.vO&~SZp}XE"YVv0s4. Such distillations must be done with all-glass apparatus at reduced pressure, to prevent decomposition of the acid. Chemical reactions can result in a change in temperature. Product and gas from reacting vinegar C2H4O2 with potash. And the rule of thumb is ", Let's understand this through an example. [23], The corrosive effects of nitric acid are exploited for some specialty applications, such as etching in printmaking, pickling stainless steel or cleaning silicon wafers in electronics.[24]. HNO 3 can behave as an oxidizing acid. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Small amounts of citric acid can be provided in plastic weighing boats or similar. The overall enthalpy of the reaction is negative, i.e., its an exothermic reaction where energy is released in the form of heat. As it decomposes to NO2 and water, it obtains a yellow tint. Combination of chlorine trifluoride and fuming nitric acid, potassium carbonate, potassium iodide, silver nitrate, 10% sodium hydroxide or sulfuric acid results in a violent reaction. Being a powerful oxidizing agent, nitric acid reacts with many non-metallic compounds, sometimes explosively. If you preorder a special airline meal (e.g. This website uses cookies and similar technologies to deliver its services, to analyse and improve performance and to provide personalised content and advertising. Magnesium, manganese, and zinc liberate H2: Nitric acid can oxidize non-active metals such as copper and silver. How would a low concentrated acetic acid react with highly concentrated KOH solution of equal volume? Dilution of nitric acid and sulphuric acid is also known as exothermic reaction as well. We've added a "Necessary cookies only" option to the cookie consent popup. Since theses are dilute solutions and are mostly water, assume that the densities of the solutions and the specific heat capacities of the solutions are approximately 1.0 g/ml and 4. . 2K (s) +2H 2 O (l) 2KOH (aq) +H 2 (g) Yet, in an endothermic reaction, I was taught the substance gets colder. Another early production method was invented by French engineer Albert Nodon around 1913. This intermediate exists at a higher energy level than the starting reactants; it is very unstable and is referred to as the transition state. Word equation: Nitric acid + Potassium hydroxide Potassium nitrate + water . Explain. Khan Academy is not suggesting that chemical bonds (ionic or covalent) are being broken. [17] Dissolved nitrogen oxides are either stripped in the case of white fuming nitric acid, or remain in solution to form red fuming nitric acid. The addition of acid encourages the equilibrium towards the right, producing more orange-coloured dichromate(VI) ions. He used a high voltage battery and non-reactive electrodes and vessels such as gold electrode cones that doubled as vessels bridged by damp asbestos.[37]. Direct link to youssefahmed3453's post So in endothermic reactio, Posted 8 days ago. I still don't understand why the fact that a weak acid does not ionise completely is an explanation as to why it is neutralised less exothermically. Last is water, which we know is H2O. Add one 3 cm piece of magnesium ribbon. Dilute hydrochloric acid, HCl(aq) see CLEAPSSHazcardHC47a and CLEAPSSRecipe Book RB043. Step-1:write the reaction. In any chemical reaction, chemical bonds are either broken or formed. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. Consider using a digital thermometer with a clear display for the demonstration. For 1416 year old students, the additionalclass practical and teacher demonstrationfeatured at the bottom of this page provides a further opportunity topractise classifying reactions as exothermic or endothermic, using test tubes instead of polystyrene cups. Calculating probabilities from d6 dice pool (Degenesis rules for botches and triggers). White fuming nitric acid, pure nitric acid or WFNA, is very close to anhydrous nitric acid. 5.5.1 Exothermic and endothermic reactions, 5.5.1.1 Energy transfer during exothermic and endothermic reactions. Hope this helps! Thanks for contributing an answer to Chemistry Stack Exchange! If the concentrations are increased then the solutions must be labelled with the correct hazard warning. I am so confused because this article is not explained well and I have no idea what is going on. An older density scale is occasionally seen, with concentrated nitric acid specified as 42Baum.[7]. . Be sure to count both of the hydrogen atoms on the reactants side of the equation. Why are neutralisations involving weak acids and bases less exothermic than those involving only strong acids and bases.? In elemental analysis by ICP-MS, ICP-AES, GFAA, and Flame AA, dilute nitric acid (0.55.0%) is used as a matrix compound for determining metal traces in solutions. The equation you gave (Hproducts - Hreactants) is also a valid equation, but the interpretation of delta H would just be the opposite of what was described above. This fluoride is added for corrosion resistance in metal tanks. If you're seeing this message, it means we're having trouble loading external resources on our website. [16], Dilute nitric acid may be concentrated by distillation up to 68% acid, which is a maximum boiling azeotrope. Stir and record the temperature after it has dissolved. C6.3 What factors affect the yield of chemical reactions? Exothermic and endothermic reactions (and changes of state). It is . In the following examples, an acid reacts with a carbonate, producing salt, carbon dioxide, and water, respectively. idk i am assuming the fridge that is in the other fridge would become colder making the food colder. Practical Chemistry activities accompanyPractical PhysicsandPractical Biology. 3. In the video labeled "Hess's law and reaction enthalpy change", the equation states H(sum of products) - H(sum of reactants). The teacher demonstration using ammonium nitrate should take no more than five minutes. Sodium hydroxide + hydrochloric acid sodium chloride + water (Neutralisation), Copper(II) sulfate + magnesium magnesium sulfate + copper (Displacement, Redox), Sulfuric acid + magnesium magnesium sulfate + hydrogen (Displacement, Redox), Sodium hydrogencarbonate + citric acid sodium citrate + water + carbon dioxide (Neutralisation), Boiling tube (a large test tube, 150 x 25 mm), Anhydrous copper(II) sulfate (HARMFUL), about 1 g, Zinc powder (HIGHLY FLAMMABLE, DANGEROUS FOR THE ENVIRONMENT), about 1 g, Ammonium nitrate crystals (OXIDISING), about 5 g. Anhydrous copper(II) sulfate (HARMFUL, DANGEROUS FOR THE ENVIRONMENT) see CLEAPSS Hazcard HC027c. Read our privacy policy. Looking at the chemical reaction, its clear that one mole of. Sodium hydroxide, NaOH(aq),(IRRITANT) see CLEAPSSHazcard HC091a and CLEAPSSRecipe Book RB085. The only part that confused me was the section involving the enthalpy equation. . Now, Sam and Julie are curious about the difference between an endothermic and an exothermic reaction. The Hsoln values given previously and in Table 8.2.2 for example, were obtained by measuring the enthalpy changes at various concentrations and extrapolating the data to infinite dilution. This is a typical acid - base reaction, and it's als. Students could investigate a variety of exothermic and endothermic reactions, including the exothermic reactions between hydrochloric acid and magnesium, nitric acid and sodium hydroxide, and . HNO 3 , (aq) + NaOH (aq) NaNO 3 (aq) + H 2 O (l) H = -57.3 kJ. [22] Ultrapure trace metal grade acid is required for such determination, because small amounts of metal ions could affect the result of the analysis. A mixture of nitric and sulfuric acids introduces a nitro substituent onto various aromatic compounds by electrophilic aromatic substitution. An exothermic process releases heat, causing the temperature of the immediate surroundings to rise. Resistance was about 3 ohms per cubic meter and the power supplied was around 10 volts. (a) Decomposition of ferrous sulphate (b) Dilution of sulphuric acid (c) Dissolution of sodium hydroxide in water (d) Dissolution of ammonium chloride in water. After neutralisation, the residue can then be poured down the foul water drain with a bucket of water. -Similarly Potassium Hydroxide is a strong base does the same. Iron(III) nitrate (Fe(NO3)3) is a strong oxidizer; skin and tissue irritant. Is the reaction of sodium hydroxide (NaOH) with nitric acid (HNO3) an exothermic or endothermic reaction? For reactions involving ethanoic acid or ammonia, the measured enthalpy change of neutralisation is a few kilojoules less exothermic than with strong acids and bases. How can this new ban on drag possibly be considered constitutional? 585 0 obj
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When a mixture of gases X and Y is compressed to 300 atm pressure and then passed over a catalyst consisting of a combination of zinc oxide and chromium oxide (heated to a temperature of 300 o C), then an organic compound Z having the molecule formula CH 4 O is formed. Repeat steps 13 of the first experiment, using copper(II) sulfate solution in place of sodium hydroxide solution. Magnesium ribbon, Mg(s) see CLEAPSSHazcard HC059a. { "Chapter_9.00:_Introduction" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.
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nitric acid and potassium hydroxide exothermic or endothermic
