However, you may visit "Cookie Settings" to provide a controlled consent. General equation: acids + metal salt + hydrogen gas Reaction between acids and metals is a type of acid-base reaction. WebUsing the definition of an acid as a "substance which donates protons (hydrogen ions) to other things", the carboxylic acids are acidic because of the hydrogen in the -COOH group. The sodium would react with the hydrochloric acid giving Na+ and Cl- ions, and hydrogen gas. The chemical equation for the reaction of sodium carbonate and hydrochloric acid is given as: Ionic form of the above equation follows: As, sodium and chloride ions are present on both the sides of the reaction. This cookie is set by GDPR Cookie Consent plugin. All carbonates react in the same sort of way and that is because the same underlying bit of chemistry happens in each case. Diarrhea. WebThe reactions and types of reaction involved are: Sodium hydroxide + hydrochloric acid sodium chloride + water (Neutralisation) NaOH (aq) + HCl (aq) NaCl (aq) + H 2 O (l) Copper (II) sulfate + magnesium magnesium sulfate + copper (Displacement, Redox) CuSO 4 (aq) + Mg (s) MgSO 4 (aq) + Cu (s) We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. $\endgroup$ Poutnik. N HCO 3+2HClNaCl+2H 2O+CO 2 B 2NaHCO 3+HClNaCl+H 2O+2CO 2 C NaHCO 3+HClNaCl+H 2O+CO 2 D 2NaHCO 3+HCl2NaCl+H 2O+CO 2 Medium Solution Verified by Toppr Correct option is C) Yes, a reaction has occurred. The sodium from sodium carbonate forms a salt with the chloride particles from the HCl, producing sodium chloride, or table salt. This change could well be represented by the ionic equation above, but if you want it, the full equation for this particular reaction is: \[ CH_3COOH + NaOH \rightarrow CH_3COONa + H_2O\]. Legal. The cookie is used to store the user consent for the cookies in the category "Analytics". Sodium carbonate is also known as sal soda, washing soda, soda ash and soda crystals. This produces two new compounds, neither one of which is a strong acid or a strong base, and is called a neutralization reaction. Analytical cookies are used to understand how visitors interact with the website. BIU Reactant Reactant appearance Evidence of chemical reaction HCG NaHCO( Predicted observation of burning match or splint Balance _NaHCO3(s) + _.HCl(a) -- _C0C@) + H2001+ NaCl(aq) Type of reaction. Many communities have large quantities of calcium and magnesium ionspositively charged particlesin the water, which prevent detergent from working as efficiently. You can build a bright future by taking advantage of opportunities and planning for success. General equation: acids + metal salt + hydrogen gas Reaction between acids and metals is a type of acid-base reaction. What type of a reaction occurs when a hydrochloric acid solution? There is very little obvious difference in the vigor of these reactions compared with the same reactions with dilute hydrochloric acid. WebWhen hydrochloric acid (chemical formula: HCl) reacts with sodium carbonate (chemical formula: Na2CO3), one of two reactions will take place, depending on the relative quantities of each chemical. Sodium bicarbonate is basic and can reacts with HCl furthermore. 1CuCO3+2HCl->CuCl2+H2O+CO2. In solution in water, a hydrogen ion is transferred from the -COOH group to a water molecule. If more HCl is added to the solution, then carbon dioxide gas, sodium chloride and water are produced. WebWhen you mix sodium carbonate and HCl, two molecules of HCl give their hydrogen atoms to the sodium carbonate. The balanced chemical equation with physical states is mentioned below. Attach a balloon to the side arm. Immediately the solution will fizz up and change the indicator to red. As the acid is all used up and the insoluble reactant has been removed, this only leaves the salt and water. The equation for the second stage of the reaction between sodium carbonate and hydrochloric acid is shown below again: NaHCO3(aq) + HCl(aq) NaCl(aq) + CO2(g) 1. Carbon dioxide is an acidic gas. Na 2 CO 3 (s) + 2HCl 2NaCl(aq) + CO 2 (g) + H 2 O(l) Step 2: Evolution of colourless gas occurs and forms an unstable carbonic acid compound. Carboxylic acids react with the more reactive metals to produce a salt and hydrogen. d) Name the type of chemical reaction which occurs. It does not store any personal data. d) Name the type of chemical reaction which occurs. We also use third-party cookies that help us analyze and understand how you use this website. Manage Settings WebThe reactions and types of reaction involved are: Sodium hydroxide + hydrochloric acid sodium chloride + water (Neutralisation) NaOH (aq) + HCl (aq) NaCl (aq) + H 2 O (l) Copper (II) sulfate + magnesium magnesium sulfate + copper (Displacement, Redox) CuSO 4 (aq) + Mg (s) MgSO 4 (aq) + Cu (s) Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. With ethanoic acid, you would eventually produce a colorless solution of calcium ethanoate. \[ 2CH_3COOH + CaCO_3 \rightarrow (CH_3COO)_2Ca + H_2O + CO_2\]. The cooling and fizzing sensation results from the endothermic reaction between sodium carbonate and a weak acid, commonly citric acid, releasing carbon dioxide gas, which occurs when the sherbet is moistened by saliva. When solutions of sodium carbonate and hydrochloric acid are mixed, the equation for the hypothetical double displacement reaction is: Na2CO3 + 2 HCl 2 NaCl + H2CO3 Bubbles of a colorless gas are evolved when these solutions are mixed. WebSodium hydrogen carbonate (N aHCO3) on reaction with hydrochloric acid (HCl) gives sodium chloride (N aCl), water (H2O) and liberates carbon dioxide (CO2). To schedule a demonstration, pleaselogin to the online lecture demonstration scheduler. HCl is the chemical formula for hydrochloric acid, which is a strong inorganicmeaning not carbon-basedacid, explains Dr. Martin Silberberg in his book "Chemistry: The Molecular Nature of Matter and Change." One mole of Natrite [Na2CO3] and two moles of Hydrogen Chloride [HCl] react to form two moles of Sodium Chloride [NaCl], one mole of Water [H2O] and one mole of Carbon Dioxide [CO2] for HCl into tubes containing Na2CO3 Cavitation caused by carbon dioxide (CO2) 2 What happens when sodium carbonate reacts with hydrochloric acid give the equation? This cookie is set by GDPR Cookie Consent plugin. In solution in water, a hydrogen ion is transferred from the -COOH group to a water molecule. An example of data being processed may be a unique identifier stored in a cookie. b) Write the balanced chemical equation for the reaction which takes place. 6 What is the ratio of HCl to sodium carbonate? The reaction is reversible, so the equilibrium shifts to the left until all of the reactants are used up. When aqueous hydrochloric acid is added to aqueous sodium carbonate (Na 2 CO 3) solution, carbon dioxide (CO 2) gas, sodium chloride (NaCl) ad water are given as products. 4 Is NaHCO3 HCl NaCl H2O CO2 a redox reaction? 3. How do you tell if a reaction is exothermic or endothermic from an equation? Hoarseness. The solution will have a green-blue color. H + OH = HO. What happens when hydrochloric acid and sodium carbonate solutions are mixed together. WebFor the reaction of sodium hydrogen carbonate and hydrochloric acid, describe the reactant appearance and identify the evidence of chemical reaction. These cookies track visitors across websites and collect information to provide customized ads. Carboxylic acids react with the more reactive metals to produce a salt and hydrogen. - Therefore, sodium carbonate is a basic salt because it is a salt derived from a weak acid and strong base. WebAcid and Metal Reactions. 1 What happens when you mix hydrochloric acid and sodium hydrogen carbonate? Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. The answer is both. But opting out of some of these cookies may affect your browsing experience. The chemical equation for the reaction of sodium carbonate and hydrochloric acid is given as: Ionic form of the above equation follows: As, sodium and chloride ions are present on both the sides of the reaction. By the type of interacting substances, it is a neutralization reaction. The carbon dioxide produced blows up the balloon. There are two ways to react sodium carbonate (A) with hydrochloric acid (B): You can add A to B, or. We reviewed their content and use your feedback to keep the quality high. H + OH = HO. Brisk effervescence is observed, indicating the presence of carbon dioxide gas. WebTo get magnesium to react with water requires the water to be hot. The pH depends on both the concentration of the acid and how easily it loses hydrogen ions from the -COOH group. How do I determine the molecular shape of a molecule? Methanoic acid is rather stronger than the other simple acids, and solutions have pH's about 0.5 pH units less than ethanoic acid of the same concentration. Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. Weba) What happens when an aqueous solution of sodium sulphate reacts with an aqueous solution of barium chloride? The equation for any strong acid being neutralized by a strong alkali is essentially just a reaction between hydrogen ions and hydroxide ions to make water. If 100 cm 3 of 1 mol dm -3 HCl solution is added to 0.04 mol Na 2 CO 3, how much carbon dioxide gas will be emitted? Also HCl can be added to solid Na 2 CO 3. 4. We also use third-party cookies that help us analyze and understand how you use this website. Carbonic acid is quite unstable, explain Drs. Drooling. Continue with Recommended Cookies. A saturated solution of sodium bicarbonate is reacted with hydrochloric acid to form carbon dioxide gas. WebThe mixing of hydrochloric acid and potassium bicarbonate would be the type of reaction known as: Bubbling is observed when potassium carbonate and hydrochloric acid solutions are mixed. Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. WebSodium hydrogen carbonate on reaction with hydrochloric acid gives sodium chloride, water and liberates carbon dioxide. Also HCl can be added to solid Na 2 CO 3. Universal indicator can be used to show the change in pH of the solution or an inflating balloon can be used to demonstrate the associated work done by the evolving gas. WebAcids will react with reactive metals, such as magnesium and zinc, to make a salt and hydrogen. By the type of interacting substances, it is a neutralization reaction. This behavior will be explained in next sections of this tutorial.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[728,90],'chemistryscl_com-medrectangle-3','ezslot_7',132,'0','0'])};__ez_fad_position('div-gpt-ad-chemistryscl_com-medrectangle-3-0'); Both aqueous sodium carbonate Sodium hydroxide solution consists of sodium ions and hydroxide ions in solution. The net ionic equation for the above reaction The mass of the system is not going to conserve if the reaction takes place in an open container: carbon dioxide escapes rapidly as the reaction proceeds, such that the mass of the products would be smaller than that of the reactants: #m("Reactants")=m("Products")# A brisk effervescence is seen in the release of carbon dioxide. Reginald Garrett and Charles Grisham in their book "Biochemistry," and falls apart into carbon dioxideCO2and water. WebCompare the rate of reaction with that of hydrochloric acid. WebStep 1: When hydrochloric acid solutions are introduced with sodium carbonate, a double displacement reaction occurs. Math app is an excellent app for many different types of equasions, the camera scanning is awesome and really helpful if u r in a hurry to finish a sum ! WebSodium bicarbonate is a weak base that reacts with hydrochloric acid to form sodium chloride and carbon dioxide. Once the vinegar is added to the baking soda, carbon dioxide is released as a product. The cookies is used to store the user consent for the cookies in the category "Necessary". Overall equation $$2HCl(aq) + 2Na(s) \rightarrow 2NaCl(aq) + H_2(g)$$ Stepwise equations. CO. 3. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. WebSodium Carbonate and Hydrochloric Acid Reaction | Na. The reactions are just the same as with acids like hydrochloric acid, except they tend to be rather slower. CO. 3. $\endgroup$ Poutnik. Necessary cookies are absolutely essential for the website to function properly. Diarrhea. WebChemical Reaction Sodium carbonate is a base that reacts with an acid, i.e., hydrochloric acid to give salt along with carbon dioxide and water. The cookie is used to store the user consent for the cookies in the category "Other. Sodium bicarbonate NaHCO3 and hydrochloric acid HCl reacts to form sodium chloride, water, and carbon dioxide- an odorless gas- by the equation NaHCO3(aq) + HCl(aq) NaCl(aq) + H2O(l) + CO2(g). + HCl. Hydrochloric acid reacts with sodium carbonate to give sodium chloride with the release of CO2 gas. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. It exists as a white powder, absorbs moisture from the air, and forms a strong alkaline aqueous solution. How do you find density in the ideal gas law. One mole of Natrite [Na2CO3] and two moles of Hydrogen Chloride [HCl] react to form two moles of Sodium Chloride [NaCl], one mole of Water [H2O] and one mole of Carbon Dioxide [CO2] for HCl into tubes containing Na2CO3 Cavitation caused by carbon dioxide (CO2) Overall equation $$2HCl(aq) + 2Na(s) \rightarrow 2NaCl(aq) + H_2(g)$$ Stepwise equations. WebNatrite + Hydrogen Chloride = Sodium Chloride + Water + Carbon Dioxide. 2. Carbonate ions from the carbonate react with hydrogen ions from the acid. Very useful app for my Algebra 1 and 2 students. The cookies is used to store the user consent for the cookies in the category "Necessary". This cookie is set by GDPR Cookie Consent plugin. Na 2 CO 3 (aq) + HCl (aq) The reactions are just the same as with acids like hydrochloric acid, except they tend to be rather slower. Hazards 6M HCl is corrosive and toxic. The other products are a solution of sodium chloride and liquid water. This mixture, also known as baking soda, is actually a type of salt. Verifying the conservation of mass for this reaction would, therefore, require trapping all gases produced within the system. $\begingroup$ Remember that carbonic acid is a weak acid and there are acido-basic equilibrii between the respective forms. There are two ways to react sodium carbonate (A) with hydrochloric acid (B): You can add A to B, or. double displacement reaction When solutions of sodium carbonate and hydrochloric acid are mixed, the equation for the hypothetical double displacement reaction is: Na2CO3 + 2 HCl 2 NaCl + H2CO3 Bubbles of a colorless gas are evolved Extension, or instead of using sodium carbonate solution: Take a small amount (one-quarter spatula measure) of solid copper carbonate on a filter paper. This cookie is set by GDPR Cookie Consent plugin. The reaction is as follows, Na 2 CO 3 s + 2 HCl aq 2 NaCl aq + CO 2 g + H 2 O l Suggest Corrections 47 Similar Like the similar-sounding compound sodium bicarbonatebaking sodait's basic, and can react with acids. WebThe mixing of hydrochloric acid and potassium bicarbonate would be the type of reaction known as: Bubbling is observed when potassium carbonate and hydrochloric acid solutions are mixed. These cookies will be stored in your browser only with your consent. In solution in water, a hydrogen ion is transferred from the -COOH group to a water molecule. Eye irritation, redness, and pain. What type of reaction is the reaction of sodium hydrogen carbonate and hydrochloric acid? WebBicarbonate Fizz Summary A saturated solution of sodium bicarbonate is reacted with hydrochloric acid to form carbon dioxide gas. What is the reaction equation for NH3 and HCl? Type of Chemical Reaction: For this reaction we have a chemical reaction. What happens when hydrochloric acid and sodium carbonate solutions are mixed together. Calculate the molarity ( M ) of HCl used in the titration of a 0-g sample of sodium carbonate that required 39 mL of the titrant (HCl) to reach the second equivalence point. This mixture, also known as baking soda, is actually a type of salt. When you add a hydrochloric acid (HCl) solution to a solution of sodium carbonate (Na 2 CO 3 ), the hydrogen ion in HCl switches places with one of the sodium ions in Na 2 CO 3 to produce sodium hydrogencarbonate, also known as sodium bicarbonate (baking soda), and sodium chloride (salt). WebThe ionic equation for the reaction. The magnesium reacts to produce a colorless solution of magnesium ethanoate, and That box of baking soda, also known as bicarbonate of soda (or sodium bicarbonate), can do some major things. Is sodium carbonate an acid? CO 32- Where was the Dayton peace agreement signed? If you mix together a solution of ethanoic acid and a solution of ammonia, you will get a colorless solution of ammonium ethanoate. Predict the observed behavior when a burning match is inserted into the test tube then balance the chemical equation and identify the type of reaction Normal . To begin balancing, put a "2" in front of the NaCl. (work = PV), \( \ce{NaHCO3_{(aq)} -> CO2_{(g)} + H2O_{(l)} + NaCl_{(aq)}} \). The first reaction we'll look at is the reaction of hydrochloric acid and sodium hydroxide, which results in sodium chloride (salt) and water. WebBicarbonate Fizz Summary A saturated solution of sodium bicarbonate is reacted with hydrochloric acid to form carbon dioxide gas. Using the definition of an acid as a "substance which donates protons (hydrogen ions) to other things", the carboxylic acids are acidic because of the hydrogen in the -COOH group. Antacid in medicine: Another important use of sodium bicarbonate is its use as an antacid. soluble inorganic This reaction is an example of a chemical process which does work. However, you would notice the difference if you used a slower reaction - for example with calcium carbonate in the form of a marble chip. A saturated solution of sodium bicarbonate is reacted with hydrochloric acid to form carbon dioxide gas. These cookies track visitors across websites and collect information to provide customized ads. Sodium bicarbonate is formed by mixing carbon, sodium, hydrogen and oxygen molecules. WebChemical Reaction Sodium carbonate is a base that reacts with an acid, i.e., hydrochloric acid to give salt along with carbon dioxide and water. The small amines are very similar indeed to ammonia in many ways. What happens when you mix hydrochloric acid and sodium hydrogen carbonate? WebWord equation: Sodium carbonate + Hydrochloric acid Sodium chloride + Water + Carbon dioxide. ), \[ CH_3COOH + H_2O \rightleftharpoons CH_3COO^- + H_3O^+\]. This website uses cookies to improve your experience while you navigate through the website. Can the Constitution be changed by the president? WebAcid reactions with carbonates and hydrogencarbonates Acids react with metal carbonates and hydrogencarbonates in the same way. Zinc reacting with hydrochloric acid produces bubbles of hydrogen gas. For example, ethanoic acid reacts with methylamine to produce a colorless solution of the salt methylammonium ethanoate. N HCO 3+2HClNaCl+2H 2O+CO 2 B 2NaHCO 3+HClNaCl+H 2O+2CO 2 C NaHCO 3+HClNaCl+H 2O+CO 2 D 2NaHCO 3+HCl2NaCl+H 2O+CO 2 Medium Solution Verified by Toppr Correct option is C) 1 What type of reaction is the reaction of sodium hydrogen carbonate and hydrochloric acid? Carbon atoms are oxidized and oxygen atoms are reduced. CO 32- This cookie is set by GDPR Cookie Consent plugin. For example, with ethanoic acid, you get an ethanoate ion formed together with a hydroxonium ion, H3O+. The cookie is used to store the user consent for the cookies in the category "Performance". If more HCl is added to the solution, then carbon dioxide Well, HCl is an acid and it reacts with the metal + HCl. The Equation of this chemical reaction is can be written as: 2HCL + Na2CO3 2NaCl + CO2 + H2O 38.1K views.This video shows you how to write the balanced molecular equation, total ionic equation, and the net ionic equation between sodium carbonate Na2CO3 and hydrochloric acid HCl. We discuss how Sodium hydrogen carbonate and hydrochloric acid balanced equation can help students learn Algebra in this blog post. The flame goes out on a burning match when sodium carbonate and hydrochloric acid are mixed because hydrogen is then present. Jun 3, 2021 at 5:05. Predict the observed behavior when a burning match is inserted into the test tube then balance the chemical equation and identify the type of reaction Normal . There are two ways to react sodium carbonate (A) with hydrochloric acid (B): You can add A to B, or. If solution is heated, carbon dioxide gas comes out easily For example, dilute hydrochloric acid contains hydrogen ions and chloride ions in solution. Additional small portions of HCl can be added until the sodium bicarbonate is consumed. Gently pour a small amount of 6 M HCl into the cylinder. What Can You Sub for Baking Powder When Making Biscuits. The equation for any strong acid being neutralized by a strong alkali is essentially just a reaction between hydrogen ions and hydroxide ions to make water. By the physical state of substances, it is homogenous. By clicking Accept All, you consent to the use of ALL the cookies. The reaction produces large quantities of carbon dioxide gas, water and table salt. A very hand-waving explanation is the following process: $$\ce{2HCl + Na2CO3 -> 2NaCl + H2CO3 -> 2NaCl + H2O + CO2}$$ The double displacement of $\ce{H+}$ and $\ce{Na}$ occurs between the $\ce{Na2CO3}$ and $\ce{HCl}$.Since the $\ce{H2CO3}$ product is unstable it will decompose at the high Sodium carbonate is an ionic compound- a sodium salt of carbonic acid, and is composed of two sodium cations ( Na + ) and a carbonate anion (CO 3- ). solution, carbon dioxide (CO2) gas, sodium chloride A very hand-waving explanation is the following process: $$\ce{2HCl + Na2CO3 -> 2NaCl + H2CO3 -> 2NaCl + H2O + CO2}$$ The double displacement of $\ce{H+}$ and $\ce{Na}$ occurs between the $\ce{Na2CO3}$ and $\ce{HCl}$.Since the $\ce{H2CO3}$ product is unstable it will decompose at the high This produces carbonic acid, with the formula H2CO3. When aqueous hydrochloric acid is added to aqueous sodium carbonate (Na2CO3) But opting out of some of these cookies may affect your browsing experience. Word equation: Sodium carbonate + Hydrochloric acid Sodium chloride + Water + Carbon dioxide. How do you know if hydrochloric acid is reacted? WebQuestion: (5pts) For the reaction of sodium hydrogen carbonate and hydrochloric acid, describe the reactant appearance and identify the evidence of chemical reaction. Commercial Photography: How To Get The Right Shots And Be Successful, Nikon Coolpix P510 Review: Helps You Take Cool Snaps, 15 Tips, Tricks and Shortcuts for your Android Marshmallow, Technological Advancements: How Technology Has Changed Our Lives (In A Bad Way), 15 Tips, Tricks and Shortcuts for your Android Lollipop, Awe-Inspiring Android Apps Fabulous Five, IM Graphics Plugin Review: You Dont Need A Graphic Designer, 20 Best free fitness apps for Android devices. WebThe mixing of hydrochloric acid and potassium bicarbonate would be the type of reaction known as: Bubbling is observed when potassium carbonate and hydrochloric acid solutions are mixed. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Na2CO3 + HCl > NaCl + CO2 + H2O Generally, acids react with metal carbonates to give out water, metal salt, and carbon dioxide. Low blood pressure (may develop rapidly) Severe pain in the mouth, throat, chest, or abdominal area. c) State the physical conditions of reactants in which the reaction will not take place. WebStep 1: When hydrochloric acid solutions are introduced with sodium carbonate, a double displacement reaction occurs. The first reaction we'll look at is the reaction of hydrochloric acid and sodium hydroxide, which results in sodium chloride (salt) and water. When hydrochloric acid is mixed with sodium hydrogen carbonate, the mixture fizzes. The cookie is used to store the user consent for the cookies in the category "Analytics". This website uses cookies to improve your experience while you navigate through the website. In both of these cases, a salt is formed together with carbon dioxide and water. 2. double displacement reaction 2023 | Powered by w3.css | The sodium from sodium carbonate forms a salt with the chloride particles from the HCl, producing sodium chloride, or table salt. Both are most easily represented by ionic equations. 8073 views What is the reaction equation for NH3 and HCl? Carbonate ions from the carbonate react with hydrogen ions from the acid. WebStep 1: When hydrochloric acid solutions are introduced with sodium carbonate, a double displacement reaction occurs. Titration of Sodium Carbonate with Hydrochloric Acid Objectives: In this experiment, a solution of Na 2 CO 3 will be titrated with a solution of HCl. 4 How do you know if hydrochloric acid is reacted? Jun 3, 2021 at 5:05. 2Al(s)+6HCl(aq)3H2(g)+2AlCl3(aq) When aluminum, AlAl, metal is dipped in an aqueous solution of hydrochloric acid, HCl, hydrogen gas, H2, is The cooling and fizzing sensation results from the endothermic reaction between sodium carbonate and a weak acid, commonly citric acid, releasing carbon dioxide gas, which occurs when the sherbet is moistened by saliva. What is the product when copper carbonate reacts with hydrochloric acid? Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. What kind of reaction is sodium hydrogen carbonate and hydrochloric acid? Finally, it liberates carbon dioxide gas and Water. (5pts) For the reaction of sodium hydrogen carbonate and hydrochloric acid, describe the reactant appearance and identify the evidence of chemical reaction.