When salt is added to the water, then cation, anion or both the ions of salt react with water and if the solution becomes either acidic or basic then it is hydrolysis process. In Leclanch cells, the aqueous solution of ammonium chloride was used as an electrolyte. For example, sodium acetate, NaCH3CO2, is a salt formed by the reaction of the weak acid acetic acid with the strong base sodium hydroxide: \[\ce{CH3CO2H}(aq)+\ce{NaOH}(aq)\ce{NaCH3CO2}(aq)+\ce{H2O}(aq) \nonumber \]. Hydrolysis involves the reaction of an organic chemical with water to form two or more new substances and usually means the cleavage of chemical bonds by the addition of water. As with other polyprotic acids, the hydrated aluminum ion ionizes in stages, as shown by: \[\ce{Al(H2O)6^3+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{Al(H2O)5(OH)^2+}(aq) \nonumber \], \[\ce{Al(H2O)5(OH)^2+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{Al(H2O)4(OH)2+}(aq) \nonumber \], \[\ce{Al(H2O)4(OH)2+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{Al(H2O)3(OH)3}(aq) \nonumber \]. Solving this equation we get [CH3CO2H] = 1.1 105 M. What is the pH of a 0.083-M solution of CN? For example, if 90% of a salt solution is hydrolysed, its degree of hydrolysis is 0.90 or as 90%. citation tool such as, Authors: Paul Flowers, Klaus Theopold, Richard Langley, William R. Robinson, PhD. Solutions that contain salts or hydrated metal ions have a pH that is determined by the extent of the hydrolysis of the ions in the solution. If you are redistributing all or part of this book in a print format, Al 1999-2023, Rice University. 2.3: Relative Strengths of Acids and Bases, Example \(\PageIndex{1}\): pH of a Solution of a Salt of a Weak Base and a Strong Acid, Example \(\PageIndex{2}\): Equilibrium of a Salt of a Weak Acid and a Strong Base, Equilibrium in a Solution of a Salt of a Weak Acid and a Weak Base, Example \(\PageIndex{3}\): Determining the Acidic or Basic Nature of Salts, Example \(\PageIndex{4}\): Hydrolysis of [Al(H2O)6]3+, status page at https://status.libretexts.org, Predict whether a salt solution will be acidic, basic, or neutral, Calculate the concentrations of the various species in a salt solution, Describe the process that causes solutions of certain metal ions to be acidic, A strong acid and a strong base, such as HCl(. After this ammonium chloride is separated, washed, and dried from the precipitate. When we neutralize a weak acid with a strong base, we get a salt that contains the conjugate base of the weak acid. The characteristic properties of aqueous solutions of Brnsted-Lowry acids are due to the presence of hydronium ions; those of aqueous solutions of Brnsted-Lowry bases are due to the presence of hydroxide ions. Without the harmful bacteria consuming the cucumbers they are able to last much longer than if they were unprotected. See Answer \(\ce{Al(H2O)6^3+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{Al(H2O)5(OH)^2+}(aq) \hspace{20px} K_\ce{a}=1.410^{5}\). not only neutralizes stomach acid, it also produces CO2(g), which may result in a satisfying belch. A) NH4+ + HCI B) No hydrolysis occurs. The acetate ion behaves as a base in this reaction; hydroxide ions are a product. Salts that form from a weak acid and a strong base are basic salts, like sodium bicarbonate (NaHCO3). Salt Hydrolysis and Equilibrium Constant: A salt made up of either 760 Specialists 4.9 Average rating What students say. 3 44) What are the products of hydrolysis of NH4Cl? This means that two of the solutions are basic (NH3 and NaF), one solution is neutral (NaCl), and the other is acidic (NH4Br). K b(NH 4OH)=1.810 5 Medium Solution Verified by Toppr Solve any question of Equilibrium with:- Patterns of problems > Was this answer helpful? It turns out that fish have volatile amines (bases) in their systems, which are neutralized by the acids to yield involatile ammonium salts. Now we have the ionization constant and the initial concentration of the weak acid, the information necessary to determine the equilibrium concentration of H3O+, and the pH: With these steps we find [H3O+] = 2.3 103 M and pH = 2.64, \(K_a\ce{(for\:NH4+)}=5.610^{10}\), [H3O+] = 7.5 106 M. \(\ce{C6H5NH3+}\) is the stronger acid (a) (b) . The hydroxide ions generated in this equilibrium then go on to react with the hydronium ions from the stomach acid, so that : This reaction does not produce carbon dioxide, but magnesium-containing antacids can have a laxative effect. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Some aquatic animals utilize ammonium chloride to maintain their buoyancy in seawater. This is the most complex of the four types of reactions. Calculate the pH of a 0.10-M solution of aluminum chloride, which dissolves completely to give the hydrated aluminum ion \(\ce{[Al(H2O)6]^3+}\) in solution. Many people like to put lemon juice or vinegar, both of which are acids, on cooked fish (Figure \(\PageIndex{1}\)). The value of pH for different substances ranges from 1 to 14 on the pH scale in which 7 is the value of pH for the neutral solution. \[\ce{C6H5NH3+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{C6H5NH2}(aq) \nonumber \]. NaCl is neutral. The dissociation chemical reaction is: NH4Cl(solid) = NH4+(aqueous) + Cl-(aqueous). Value of Ka or Kb? When water and salts react, there are many possibilities . Solving this equation we get [CH3CO2H] = 1.1 105 M. What is the pH of a 0.083-M solution of CN? Note that some of these aluminum species are exhibiting amphiprotic behavior, since they are acting as acids when they appear on the left side of the equilibrium expressions and as bases when they appear on the right side. The word neutralization seems to imply that a stoichiometrically equivalent solution of an acid and a base would be neutral. The constants for the different stages of ionization are not known for many metal ions, so we cannot calculate the extent of their ionization. Neutralization is the reaction between an acid and a base that results in the formation of a salt that derives its properties from its constituent i.e. 6 The Ka of HPO42HPO42 is 4.2 1013. NH4Cl is not a base as it does not fit into the definition of base given by any of the acid-base theory viz. Responses Chemistry - DrBob222, Friday, April 24, 2009 at 10:50pm The hydrolysis of Na2CO3 ends us as the hydrolysis of the carbonate ion. Why is NH4Cl acidic? 2 We will not find a value of Ka for the ammonium ion in Table E1. If we want to determine a Kb value using one of these handbooks, we must look up the value of Ka for the conjugate acid and convert it to a Kb value. Thus, the hydration becomes important and we may use formulas that show the extent of hydration: \[\ce{Al(H2O)6^3+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{Al(H2O)5(OH)^2+}(aq) \hspace{20px} K_\ce{a}=1.410^{5} \nonumber \]. When we have heartburn, it feels better if we reduce the excess acid in the esophagus by taking an antacid. ZnCl2. To learn more about the Structure, Properties, Preparation, Uses and FAQs of Ammonium Chloride (NH4Cl), Visit BYJU'S for more content. In anionic hydrolysis, the pH of the solution will be above 7. However, the acetate ion, the conjugate base of acetic acid, reacts with water and increases the concentration of hydroxide ion: \[\ce{CH3CO2-}(aq)+\ce{H2O}(l)\ce{CH3CO2H}(aq)+\ce{OH-}(aq) \nonumber \]. The pH value of a substance is an indicator of the acidity or basicity of that substance in its aqueous solution. When an aluminum ion reacts with water, the hydrated aluminum ion becomes a weak acid. The brine solution favors the growth of beneficial bacteria and suppresses the growth of harmful bacteria. Arrhenius theory: A molecule that produces hydroxide ion (OH-) in a solution is a base and the molecule which is unable to produce hydroxide ions is an acid. NH4OH + HClE. Since ammonia is a weak base, Kb is measurable and Ka > 0 (ammonium ion is a weak acid). 3 At the same time, the NH4Cl is a very different substance than NH4+ and Cl-.If you need to know how to balance chemical reactions, see my complete tutorial on balancing all types of chemical equations:Balancing Equations in 5 Easy Steps: https://youtu.be/zmdxMlb88FsMore Practice Balancing: https://youtu.be/Qci7hiBy7EQDrawing/writing done in InkScape. Except where otherwise noted, textbooks on this site Substituting the expressions for the equilibrium concentrations into the equation for the ionization constant yields: \(=\dfrac{(x)(x)}{0.10x}=1.4 \times 10^{5}\), \[\ce{[H3O+]}=0+x=1.210^{3}\:M \nonumber \], \[\mathrm{pH=log[H_3O^+]=2.92(an\: acidic\: solution)} \nonumber \]. The molecular formula. Milk of Magnesia is a suspension of the sparingly soluble base magnesium hydroxide, Mg(OH)2. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . Now as explained above the number of H+ ions will be more than the number . It works according to the reaction: \[Mg(OH)_2(s)Mg^{2+}(aq)+2OH^-(aq) \nonumber \]. They only report ionization constants for acids. This can also be justified by understanding further hydrolysis of these ions. The pH value for NH4Cl lies between 4.5 and 6 and its pKa value is 9.24, therefore, it is mildly acidic. A) H H H H B) N + H H H H H-F H1 H D) H F " H E) 2+ 2- N H H H. A solution is neutral when it contains equal concentrations of hydronium and hydroxide ions. This reduces the odor of the fish, and also adds a sour taste that we seem to enjoy. salt hydrolysis: A reaction in which one of the ions from a salt reacts with water, forming either an acidic or basic solution. $$\ce{NH4+ + H2O <=> NH4OH + H+}$$ Now for . When the conjugate acid and the conjugate base are of unequal strengths, the solution can be either acidic or basic, depending on the relative strengths of the two conjugates. It is isolated as aniline hydrochloride, \(\ce{[C6H5NH3+]Cl}\), a salt prepared by the reaction of the weak base aniline and hydrochloric acid. In the case of NH4Cl the dissociation equation can be written as: Here, the NH4Cl hydrolysis to form an NH4+ ion, which is the conjugate acid of ammonia, while the Cl- ion which is the conjugate base of ammonia. 11 Uses of Platinum Laboratory, Commercial, and Miscellaneous, CH3Br Lewis Structure, Geometry, Hybridization, and Polarity. This conjugate base is usually a weak base. This relation holds for any base and its conjugate acid or for any acid and its conjugate base. (c) The Na+ cation is inert and will not affect the pH of the solution, while the HPO42HPO42 anion is amphiprotic. For example, ammonium chloride, NH4Cl, is a salt formed by the reaction of the weak base ammonia with the strong acid HCl: \[\ce{NH3}(aq)+\ce{HCl}(aq)\ce{NH4Cl}(aq) \nonumber \]. Expression for equilibrium constant (Ka or Kb)? The Ka of HCO3HCO3 is 4.7 1011,and its Kb is 1.010144.3107=2.3108.1.010144.3107=2.3108. If Ka > Kb, the solution is acidic, and if Kb > Ka, the solution is basic. The reaction, \[CaCO_3(s)+2HCl(aq)CaCl_2(aq)+H_2O(l)+CO_2(g) \nonumber \]. Ammonium Chloride is denoted by the chemical formula NH4Cl. Ammonium Chloride (NH4Cl) - Ammonium chloride is an inorganic compound with formula NH4Cl. Example #1: What is the pH of a 0.0500 M solution of ammonium chloride, NH 4 Cl. For example, dissolving sulfuric acid in water yields hydronium and bisulfate. 3+ As you may have guessed, antacids are bases. Conjugates of weak acids or bases are also basic or acidic (reverse. and you must attribute OpenStax. In this case the cation reacts with water to give an acidic solution. Therefore, it is an acidic salt. According to Arrheniuss theory of acids and bases, acids are the compounds that release hydrogen or hydronium ions upon their dissociation in an aqueous solution. Hydrolysis reactions occur when organic compounds react with water. The pH value for NH4Cl lies between 4.5 and 6 and its pKa value is 9.24. A. It is odorless with a density of 1.519 gm/cm3, It has a pH value between 4.5 and 6 and its pKa value is 9.24. Michael Clifton Other than that the app is great, honestly with my good professor, i didnt need to focus on the homework, wow this app is awesome actually this app was the one which solve my . If Ka > Kb, the solution is acidic, and if Kb > Ka, the solution is basic. https://openstax.org/books/chemistry-2e/pages/1-introduction, https://openstax.org/books/chemistry-2e/pages/14-4-hydrolysis-of-salts, Creative Commons Attribution 4.0 International License, Predict whether a salt solution will be acidic, basic, or neutral, Calculate the concentrations of the various species in a salt solution, Describe the acid ionization of hydrated metal ions. It naturally occurs in the form of a mineral called sal ammoniac. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. Save my name, email, and website in this browser for the next time I comment. Answer: NH and H Explanation: The dissociation of NHCl will lead to two ions , i.e. Calculate (i) the degree of hydrolysis (ii) the hydrolysis constant and (iii) When aluminum nitrate dissolves in water, the aluminum ion reacts with water to give a hydrated aluminum ion, \(\ce{Al(H2O)6^3+}\), dissolved in bulk water. CO Solve for x and the equilibrium concentrations. The second column is blank. It occurs near the volcanoes and forms volcanic rocks near fumaroles. The burning sensation associated with heartburn is a result of the acid of the stomach leaking through the muscular valve at the top of the stomach into the lower reaches of the esophagus. However, as ammonium chloride is easily available as a by-product in double decomposition reactions, therefore, being cost-effective they are more favored. However, the ionization of a cation carrying more than one charge is usually not extensive beyond the first stage. Using the provided information, an ICE table for this system is prepared: Substituting these equilibrium concentration terms into the Ka expression gives. The lining of the esophagus is not protected from the corrosive effects of stomach acid the way the lining of the stomach is, and the results can be very painful. Lastly, the reaction of a strong acid with a strong base gives neutral salts. This page titled 2.4: Hydrolysis of Salt Solutions is shared under a CC BY license and was authored, remixed, and/or curated by OpenStax. Check the work. Because Kb >> Ka, the solution is basic. CH Ionization increases as the charge of the metal ion increases or as the size of the metal ion decreases. As mentioned in the other answer, NH4Cl is an "acidic" salt, formed by the neutralization of a strong acid (HCl) with a weak base (NH3) . It could contain either an excess of hydronium ions or an excess of hydroxide ions because the nature of the salt formed determines whether the solution is acidic, neutral, or basic. Ammonium chloride in water is acidic and it produces ammonia, H+ ions, Cl- ions and H2O. Solutions that contain salts or hydrated metal ions have a pH that is determined by the extent of the hydrolysis of the ions in the solution. Check the work. Ka, for the acid \(\ce{NH4+}\): \[\ce{\dfrac{[H3O+][NH3]}{[NH4+]}}=K_\ce{a} \nonumber \]. Because acetic acid is a weak acid, its Ka is measurable and Kb > 0 (acetate ion is a weak base). A strong acid and a weak base yield a weakly acidic solution, not because of the strong acid involved, but because of the conjugate acid of the weak base. The bromide ion is the conjugate base of a strong acid, and so it is of negligible base strength (no appreciable base ionization). Chloride is a very weak base and will not accept a proton to a measurable extent. 2022 - 2023 Times Mojo - All Rights Reserved In cationic hydrolysis, the solution becomes slightly acidic (p H <7). In a solution of a salt formed by the reaction of a weak acid and a weak base, to predict the pH, we must know both the Ka of the weak acid and the Kb of the weak base. (2) If the acid produced is weak and the base produced is strong. This process is known as anionic hydrolysis. The new step in this example is to determine Ka for the \(\ce{C6H5NH3+}\) ion. One of the most common antacids is calcium carbonate, CaCO3. It was postulated that ammonia . Calculate the hydrolysis constant of NH 4Cl. HF ( a q) + NaOH ( a q) NaF ( a q) + H 2 O ( l) HF ( a q) + OH ( a q) F ( a q) + H 2 O ( l) Since sodium fluoride is soluble, the sodium ion is a spectator ion in the neutralization reaction. C) NH3 + H3O+ + Cl- DUHOXHCL E) NH3 + OH- + HCI 49) Which diagram best represents the products when equimolar amounts of HF (g) and NH3 (g) react? This may seem obvious from the ion's formula, which indicates no hydrogen or oxygen atoms, but some dissolved metal ions function as weak acids, as addressed later in this section. This is sometimes true, but the salts that are formed in these reactions may have acidic or basic properties of their own, as we shall now see. Bronsted-Lowry theory: A molecule that readily gives away protons in an aqueous solution is an acid while the molecule that takes up those protons, given away by another molecule, is a base. If you could please show the work so I can understand for the rest of them. Salts that form from a strong acid and a weak base are acid salts, like ammonium chloride (NH4Cl). The brine solution favors the growth of beneficial bacteria and suppresses the growth of harmful bacteria. When NH 4 Cl goes through the hydrolysis process, it split into two ions (NH 4+ + Cl - ). Screen capture done with Camtasia Studio 4.0. The reaction, \[CaCO_3(s)+2HCl(aq)CaCl_2(aq)+H_2O(l)+CO_2(g) \nonumber \]. Substituting the expressions for the equilibrium concentrations into the equation for the ionization constant yields: Assuming x << 0.10 and solving the simplified equation gives: The ICE table defined x as equal to the hydronium ion concentration, and so the pH is calculated to be. A solution of this salt contains ammonium ions and chloride ions. CO The lactic acid eventually increases the acidity of the brine to a level that kills any harmful bacteria, which require a basic environment. The major use of ammonium chloride is in nitrogen-based fertilizers. The sodium ion has no effect on the acidity of the solution. Use 4.9 1010 as Ka for HCN. One example is the use of baking soda, or sodium bicarbonate in baking. We determine Kb as follows: \[K_\ce{b}=\ce{\dfrac{[CH3CO2H][OH- ]}{[CH3CO2- ]}}=5.610^{10} \nonumber \], \[=\dfrac{[\ce{CH3CO2H}](2.510^{6})}{(0.050)}=5.610^{10} \nonumber \]. Which of the following salts will undergo cationic hydrolysis? The reaction is: We are given two of three equilibrium concentrations and asked to find the missing concentration. (If this occurs in other solvents, it will be called 'solvolysis' or just the name of solvent plus -lysis such as ethanolysis.) As you may have guessed, antacids are bases. Legal. The constants for the different stages of ionization are not known for many metal ions, so we cannot calculate the extent of their ionization. NaHCO3 is a base. Dissociation constant of NH 4OH is 1.810 5. It turns out that fish have volatile amines (bases) in their systems, which are neutralized by the acids to yield involatile ammonium salts. I am Savitri,a science enthusiast with a passion to answer all the questions of the universe. It's a site that collects all the most frequently asked questions and answers, so you don't have to spend hours on searching anywhere else. This relation holds for any base and its conjugate acid or for any acid and its conjugate base. Likewise, some salts contain a single ion that is amphiprotic, and so the relative strengths of this ions acid and base character will determine its effect on solution pH. Milk of Magnesia is a suspension of the sparingly soluble base magnesium hydroxide, Mg(OH)2. It is a salt of a strong acid and a weak base. When we mix solutions of an acid and a base, an acid-base neutralization reaction occurs. But this pH dependent reaction yields different products. , NH and Cl . So the ions present in the Solution of NH4Cl, will be, NH4+ , Cl-, H+, OH-. This is the most complex of the four types of reactions. ( It is a reaction which is shown by a salt made by the reaction of a strong acid and a weak base. The equilibrium equation for this reaction is simply the ionization constant. Considering all the above-mentioned theories this can be easily deciphered that the properties of ammonium chloride molecule do not fit into the definition of the base, rendered by any of these theories, therefore, NH4Cl is not a base. The equilibrium equation for this reaction is simply the ionization constant. For both types of salts, a comparison of the Ka and Kb values allows prediction of the solutions acid-base status, as illustrated in the following example exercise. Ammonium ions undergo hydrolysis to form NH4OH. A strong base produces a weak conjugate acid. As seen in the above equation on dissolving in aqueous solution NH4Cl releases hydronium ions due to the hydrolysis of ammonium ions. The aluminum ion is an example. , is the conjugate base of acetic acid, CH3CO2H, and so its base ionization (or base hydrolysis) reaction is represented by. Many people like to put lemon juice or vinegar, both of which are acids, on cooked fish (Figure \(\PageIndex{1}\)). Ammonium Chloride is an acidic salt. The third column has the following: approximately 0, x, x. Determine whether aqueous solutions of the following salts are acidic, basic, or neutral: Consider each of the ions separately in terms of its effect on the pH of the solution, as shown here: If we measure the pH of the solutions of a variety of metal ions we will find that these ions act as weak acids when in solution. Ammonium Chloride is majorly manufactured as a by-product of the Solvay process which is used for the production of Sodium Carbonate. Why is an aqueous solution of NH4Cl Acidic? $$\ce {RCN + 2H2O + HCl -> RCOOH + NH4Cl}$$. However, in this case, the hydrated aluminum ion is a weak acid (Figure \(\PageIndex{2}\)) and donates a proton to a water molecule. \(\ce{Al(H2O)6^3+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{Al(H2O)5(OH)^2+}(aq) \hspace{20px} K_\ce{a}=1.410^{5}\). What is the approximately pH of a 0.1M solution of the salt. In a solution of a salt formed by the reaction of a weak acid and a weak base, to predict the pH, we must know both the Ka of the weak acid and the Kb of the weak base. A strong acid and a weak base yield a weakly acidic solution, not because of the strong acid involved, but because of the conjugate acid of the weak base. Comparing the two ionization constants: Ka of NH4+NH4+ is 5.6 1010 and the Kb of F is 1.6 1011, so the solution is acidic, since Ka > Kb. When aluminum nitrate dissolves in water, the aluminum ion reacts with water to give a hydrated aluminum ion, \(\ce{Al(H2O)6^3+}\), dissolved in bulk water. We frequently see the formula of this ion simply as Al3+(aq), without explicitly noting the six water molecules that are the closest ones to the aluminum ion and just describing the ion as being solvated in water (hydrated). You'll get a detailed solution from a subject matter expert that helps you learn core concepts. All the substances having a pH value below 7 are acidic while the substances having a pH value above 7 are basic. Ammonium Chloride naturally occurs as a mineral called sal ammoniac. Solve for x and the equilibrium concentrations. The neutralization that occurs when aqueous solutions of acids and bases are combined results from the reaction of the hydronium and hydroxide ions to form water. Therefore, the pH of NH4Cl should be less than 7. However, practically all hydrated metal ions other than those of the alkali metals ionize to give acidic solutions. NH4+(aqueous) +H2O(liquid) = NH3(aqueous) +H3O+(aqueous) H3O+ +OH- = 2H2O. Therefore, NH4+ is a strong conjugate acid while Cl- is a weak conjugate base. While basic salt is formed by the combination of weak acid along with a strong base. Similarly, NaF is basic (it is the salt of a strong base, NaOH, and a weak acid, HF). Home | About | Contact | Copyright | Report Content | Privacy | Cookie Policy | Terms & Conditions | Sitemap. This conjugate acid is a weak acid. The \(\ce{C6H5NH3+}\) ion is the conjugate acid of a weak base. Ka, for the acid \(\ce{NH4+}\): \[\ce{\dfrac{[H3O+][NH3]}{[NH4+]}}=K_\ce{a} \nonumber \]. It is a salt of a strong acid and a weak base, which are hydrochloric acid and ammonia, respectively. ----- NH4Cl. A solution of a weak acid reacts with a solution of a strong base to form the conjugate base of the weak acid and the conjugate acid of the strong base. Copper sulphate will form an acidic solution. Determine the acetic acid concentration in a solution with \(\ce{[CH3CO2- ]}=0.050\:M\) and [OH] = 2.5 106 M at equilibrium. The new step in this example is to determine Ka for the \(\ce{C6H5NH3+}\) ion. Your email address will not be published. For example, sodium acetate, NaCH3CO2, is a salt formed by the reaction of the weak acid acetic acid with the strong base sodium hydroxide: \[\ce{CH3CO2H}(aq)+\ce{NaOH}(aq)\ce{NaCH3CO2}(aq)+\ce{H2O}(aq) \nonumber \]. : a chemical process of decomposition involving the splitting of a bond and the addition of the hydrogen cation and the hydroxide anion of water. In anionic hydrolysis, the solution becomes slightly basic (p H >7). Want to cite, share, or modify this book? Thus, dissolving ammonium chloride in water yields a solution of weak acid cations (NH4+NH4+) and inert anions (Cl), resulting in an acidic solution. We determine Kb as follows: \[K_\ce{b}=\ce{\dfrac{[CH3CO2H][OH- ]}{[CH3CO2- ]}}=5.610^{10} \nonumber \], \[=\dfrac{[\ce{CH3CO2H}](2.510^{6})}{(0.050)}=5.610^{10} \nonumber \]. On the other hand, the NH4+ ion gives away its proton to form a hydronium ion with the water molecule. Additional examples of the first stage in the ionization of hydrated metal ions are: \[\ce{Fe(H2O)6^3+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{Fe(H2O)5(OH)^2+}(aq) \hspace{20px} K_\ce{a}=2.74 \nonumber \], \[\ce{Cu(H2O)6^2+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{Cu(H2O)5(OH)+}(aq) \hspace{20px} K_\ce{a}=~6.3 \nonumber \], \[\ce{Zn(H2O)4^2+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{Zn(H2O)3(OH)+}(aq) \hspace{20px} K_\ce{a}=9.6 \nonumber \]. \[\ce{C6H5NH3+}(aq)+\ce{H2O}(l)\ce{H3O+}(aq)+\ce{C6H5NH2}(aq) \nonumber \]. NH4Cl is used as a urinary acidifying salt as it helps in maintaining the pH and exhibits a diuretic effect.