Amines, which are organic analogues of ammonia, are also weak bases, as are ionic compounds that contain anions derived from weak acids (such as S2). Acid Base Reaction Example Hydrochloric acid and Sodium hydroxide Hydrochloric acid is a strong acid. \(HClO_4(l) \rightarrow H^+(aq) + ClO_4^-(aq)\), The H+ ion concentration is therefore the same as the perchloric acid concentration. Classify each compound as a strong acid, a weak acid, a strong base, a weak base, or none of these. What is the molarity of the final solution? According to Brnsted and Lowry, an acid (A substance with at least one hydrogen atom that can dissociate to form an anion and an \(H^+\) ion (a proton) in aqueous solution, thereby forming an acidic solution) is any substance that can donate a proton, and a base (a substance that produces one or more hydroxide ions (\(OH^-\) and a cation when dissolved in aqueous solution, thereby forming a basic solution) is any substance that can accept a proton. The other product is water. Acids also differ in their tendency to donate a proton, a measure of their acid strength. It dissociates completely in an aqueous solution and gives arise to H+ and Cl-. A base that dissociates essentially completely in water) to give \(OH^-\) and the corresponding cation), An acid in which only a fraction of the molecules react with water) to producee, (A base in which only a fraction of the molecules react with water to produce. In ancient times, an acid was any substance that had a sour taste (e.g., vinegar or lemon juice), caused consistent color changes in dyes derived from plants (e.g., turning blue litmus paper red), reacted with certain metals to produce hydrogen gas and a solution of a salt containing a metal cation, and dissolved carbonate salts such as limestone (CaCO3) with the evolution of carbon dioxide. The chemical equation for this reaction is: An example, using ammonia as the base, is H2O + NH3 OH + NH4+. In BrnstedLowry terms, an acid is a substance that can donate a proton (H+), and a base is a substance that can accept a proton. Technically, therefore, it is imprecise to describe the dissociation of a strong acid as producing \(H^+_{(aq)}\) ions, as we have been doing. A 25.00 mL sample of a 0.9005 M solution of HCl is diluted to 500.0 mL. In fact, every amateur chef who has prepared mayonnaise or squeezed a wedge of lemon to marinate a piece of fish has carried out an acidbase reaction. If a typical household cleanser is 0.50 M in strong base, what volume of 0.998 M strong monoprotic acid is needed to neutralize 50.0 mL of the cleanser? HI and NaOH are both strong acid and base respectively. Because one factor that is believed to contribute to the formation of stomach ulcers is the production of excess acid in the stomach, many individuals routinely consume large quantities of antacids. Examples of the last two are as follows: \[ \underset{strong\: acid}{HCl(aq)} + \underset{weak\: base}{NH_3 (aq)} \rightarrow \underset{salt}{NH_4 Cl(aq)} \], \[ \underset{weak\: acid} {CH_3 CO _2 H(aq)} + \underset{strong\: base}{NaOH(aq)} \rightarrow \underset{salt}{CH _3 CO _2 Na(aq)} + H_2 O(l) \]. Calcium fluoride and rubidium sulfate. Although these definitions were useful, they were entirely descriptive. H2SO4 + NH3 NH4+ + SO42-. . Second, and more important, the Arrhenius definition predicted that, none of these; formaldehyde is a neutral molecule. AboutTranscript. One was proposed independently in 1923 by the Danish chemist J. N. Brnsted (18791947) and the British chemist T. M. Lowry (18741936), who defined acidbase reactions in terms of the transfer of a proton (H+ ion) from one substance to another. Neutralization Reaction Equation acid + base (alkali) salt + water Neutralization Reaction Equation )%2F04%253A_Reactions_in_Aqueous_Solution%2F4.03%253A_Acid-Base_Reactions, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), A substance with at least one hydrogen atom that can dissociate to form an anion and an, (a substance that produces one or more hydroxide ions (\(OH^-\) and a cation when dissolved in aqueous solution, thereby forming a basic solution), (a compound that is capable of donating one proton per molecule), A compound that can donate more than one proton per molecule is known as a, compound that can donate two protons per molecule in separate steps). The only common strong bases are the hydroxides of the alkali metals and the heavier alkaline earths (Ca, Sr, and Ba); any other bases you encounter are most likely weak. We will not discuss the strengths of acids and bases quantitatively until next semester. A neutralization reaction is when an acid and a base react to form water and a salt and involves the combination of H+ ions and OH . All acidbase reactions involve two conjugate acidbase pairs, the BrnstedLowry acid and the base it forms after donating its proton, and the BrnstedLowry base and the acid it forms after accepting a proton. First, because acids and bases were defined in terms of ions obtained from water, the Arrhenius concept applied only to substances in aqueous solution. Neutralization Reaction - Acid-Base Reaction to form Salt and Water Relation Between the Strength of Reactants and Resultant pH Depending upon the strength of the constituent acids and bases the pH of the products varies. Acids provide the H + ion; bases provide the OH - ion; these ions combine to form water. Figure 8.7.2 A Plot of pH versus [H+] for Some Common Aqueous Solutions. Each carbonate ion can react with 2 mol of H+ to produce H2CO3, which rapidly decomposes to H2O and CO2. our Math Homework Helper is here to help. The BrnstedLowry definition of an acid is essentially the same as the Arrhenius definition, except that it is not restricted to aqueous solutions. In fact, this is only one possible set of definitions. A salt and hydrogen are produced when acids react with metals. We can define acids as substances that dissolve in water to produce H+ ions, whereas bases are defined as substances that dissolve in water to produce OH ions. Acids react with metal carbonates and hydrogencarbonates in the same way. Before we discuss the characteristics of such reactions, lets first describe some of the properties of acids and bases. When these two substances are mixed, they react to form carbon dioxide gas, water, and sodium acetate. The human stomach contains an approximately 0.1 M solution of hydrochloric acid that helps digest foods. Remember that there is no correlation between solubility and whether a substance is a strong or a weak electrolyte! How many Tums tablets are required to neutralize 90% of the stomach acid, if each tablet contains 500 mg of CaCO3? 15 Facts on HI + NaOH: What, How To Balance & FAQs. The active ingredients in antacids include sodium bicarbonate and potassium bicarbonate (NaHCO3 and KHCO3; Alka-Seltzer); a mixture of magnesium hydroxide and aluminum hydroxide [Mg(OH)2 and Al(OH)3; Maalox, Mylanta]; calcium carbonate (CaCO3; Tums); and a complex salt, dihydroxyaluminum sodium carbonate [NaAl(OH)2CO3; original Rolaids]. Weak acid vs strong base. Instead, the solution contains significant amounts of both reactants and products. The sodium hydroxide is a strong base, it dissociates in Na+ and OH-. Colorless to white, odorless Solve Now. The most common weak base is ammonia, which reacts with water to form small amounts of hydroxide ion: \[ NH_3 (g) + H_2 O(l) \rightleftharpoons NH_4^+ (aq) + OH^- (aq) \]. The aluminum metal ion has an unfilled valence shell, so it . An acid-base reaction is a chemical reaction that occurs between an acid and a base.It can be used to determine pH via titration.Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid-base theories, for example, Brnsted-Lowry acid-base theory. Similarly, strong bases (A base that dissociates essentially completely in water) to give \(OH^-\) and the corresponding cation) dissociate essentially completely in water to give \(OH^\) and the corresponding cation. Many weak acids and bases are extremely soluble in water. B If inorganic, determine whether the compound is acidic or basic by the presence of dissociable H+ or OH ions, respectively. A chemist needed a solution that was approximately 0.5 M in HCl but could measure only 10.00 mL samples into a 50.00 mL volumetric flask. General acid-base reactions, also called neutralization reactions can be summarized with the following reaction equation: ACID (aq) + BASE (aq) H 2 O (l) + SALT (aq) or (s) The DRIVING FORCE for a general acid-base reaction is the formation of water. This type of reaction is referred to as a neutralization reaction because it . Gas-forming acid-base reactions can be summarized with the following reaction equation: Equation \(\PageIndex{231}\) : \(pH = -log[H^+]\), Equation \(\PageIndex{24}\) : \([H^+] = 10^{-pH}\). We will discuss these reactions in more detail in Chapter 16. The reaction is as below. Most of the ammonia (>99%) is present in the form of NH3(g). If the product had been cesium iodide, what would have been the acid and the base? Qualitatively, however, we can state that strong acids (An acid that reacts essentially completely with water) to give \(H^+\) and the corresponding anion. Acids other than the six common strong acids are almost invariably weak acids. B If inorganic, determine whether the compound is acidic or basic by the presence of dissociable H+ or OH ions, respectively. Mathematical equations are a way of representing mathematical relationships between variables. An acid-base reaction is a type of double displacement reaction that occurs between an acid and a base. The only common strong bases are the hydroxides of the alkali metals and the heavier alkaline earths (Ca, Sr, and Ba); any other bases you encounter are most likely weak. In Equation \(\PageIndex{11}\), for example, the products of the reaction are the hydronium ion, here an acid, and the hydrogen sulfate ion, here a weak base. . The proton and hydroxyl ions combine to Solve Now 10 word . Amines, which are organic analogues of ammonia, are also weak bases, as are ionic compounds that contain anions derived from weak acids (such as S2). Qualitatively, however, we can state that strong acids react essentially completely with water to give \(H^+\) and the corresponding anion. The H + ion in the acid reacts with the OH - ion in the base to form water and an ionic salt: HA + BOH H 2 O + BA. What is the complete ionic equation for each reaction? 4.4. If 20.0 mL of 0.10 M NaOH are needed to neutralize 15.0 mL of gastric fluid, what is the molarity of HCl in the fluid? For example ammonium, which we usually consider a base when in an aqueous solution, can act as a solvent and do similar acid-base reactions that water does. Table \(\PageIndex{1}\) lists some common strong acids and bases. Each has certain advantages and disadvantages. Equation: Acidic medium. What is the relationship between the strength of an acid and the strength of the conjugate base derived from that acid? According to Brnsted and Lowry, an acid (A substance with at least one hydrogen atom that can dissociate to form an anion and an \(H^+\) ion (a proton) in aqueous solution, thereby forming an acidic solution) is any substance that can donate a proton, and a base (a substance that produces one or more hydroxide ions (\(OH^-\) and a cation when dissolved in aqueous solution, thereby forming a basic solution) is any substance that can accept a proton. Acid + Base Water + Salt. Examples of strong acid-weak base neutralization reaction 10. The product NH4+ is called the conjugate acidThe substance formed when a BrnstedLowry base accepts a proton. compound that can donate two protons per molecule in separate steps). ), Given: volume and molarity of acid and mass of base in an antacid tablet, Asked for: number of tablets required for 90% neutralization. There is no correlation between the solubility of a substance and whether it is a strong electrolyte, a weak electrolyte, or a nonelectrolyte. Although the general properties of acids and bases have been known for more than a thousand years, the definitions of acid and base have changed dramatically as scientists have learned more about them. In some cases, the reaction of an acid with an anion derived from a weak acid (such as HS) produces a gas (in this case, H2S). Example 2: Another example of divalent acids and bases represents the strength of . In Equation \(\PageIndex{12}\), the products are NH4+, an acid, and OH, a base. Note that both show that the pH is 1.7, but the pH meter gives a more precise value. For example, monoprotic acids (a compound that is capable of donating one proton per molecule) are compounds that are capable of donating a single proton per molecule. For example, the reaction of equimolar amounts of HBr and NaOH to give water and a salt (NaBr) is a neutralization reaction: \[ \underset{acid}{HBr(aq)} + \underset{base}{NaOH(aq)} \rightarrow \underset{water}{H_2 O(l)} + \underset{salt}{NaBr(aq)} \]. react essentially completely with water to give \(H^+\) and the corresponding anion. . In an aqueous solution, water will self-ionize meaning that two water molecules engage in an acid-base reaction and create a hydronium and hydroxide ion. Placing a drop of a solution on a strip of pH paper and comparing its color with standards give the solutions approximate pH. Ammonium nitrate is famous in the manufacture of explosives. All carboxylic acids that contain a single CO2H group, such as acetic acid (CH3CO2H), are monoprotic acids, dissociating to form RCO2 and H+. Following are some of the examples which will help you to understand the process and reaction taking place between acid and base which will give the end product as a salt. Because the autoionization reaction of water does not go to completion, neither does the neutralization reaction. Acid Base Neutralization Reactions & Net Ionic Equations. Common weak acids include HCN, H2S, HF, oxoacids such as HNO2 and HClO, and carboxylic acids such as acetic acid. Malonic acid (C3H4O4) is a diprotic acid used in the manufacture of barbiturates. Second, and more important, the Arrhenius definition predicted that. The ionization reaction of acetic acid is as follows: \[ CH_3 CO_2 H(l) \overset{H_2 O(l)}{\rightleftharpoons} H^+ (aq) + CH_3 CO_2^- (aq) \label{4.3.7} \]. Pure liquid water contains extremely low but measurable concentrations of H3O+(aq) and OH(aq) ions produced via an autoionization reaction, in which water acts simultaneously as an acid and as a base: \[H_2O(l) + H_2O(l) \rightleftharpoons H_3O^+(aq) + OH^-(aq)\tag{8.7.22}\). Figure 8.6.3 Two Ways of Measuring the pH of a Solution: pH Paper and a pH Meter. Because of the limitations of the Arrhenius definition, a more general definition of acids and bases was needed. What specific point does the BrnstedLowry definition address? NaOH is a corrosive white crystalline solid that readily absorbs moisture from the air. Instead, the proton is always transferred to another substance, which acts as a base in the BrnstedLowry definition. Compounds that are capable of donating more than one proton are generally called polyprotic acids. In fact, this is only one possible set of definitions. Ka and acid strength. For example, the balanced chemical equation for the reaction between HCl (aq) and KOH (aq) is \( 2H^+ + 2NO_3^- + Ca^{2+} + 2OH^- \rightarrow Ca^{2+} + 2NO_3^- + H_2O\) Strong base solutions. Ammonia, for example, reacts with a proton to form \(NH_4^+\), so in Equation \(\ref{4.3.3}\), \(NH_3\) is a BrnstedLowry base and \(HCl\) is a BrnstedLowry acid. Moreover, many of the substances we encounter in our homes, the supermarket, and the pharmacy are acids or bases. The proton and hydroxyl ions combine to. Except for the reaction of a weak acid or a weak base with water, acidbase reactions essentially go to completion. Over time, the reaction reaches a state in which the concentration of each species in solution remains constant. Consequently, an aqueous solution of sulfuric acid contains \(H^+_{(aq)}\) ions and a mixture of \(HSO^-_{4\;(aq)}\) and \(SO^{2}_{4\;(aq)}\) ions, but no \(H_2SO_4\) molecules. Decide whether each compound forms an aqueous solution that is strongly acidic, weakly acidic, strongly basic, or weakly basic. The reaction of a strong acid with a strong base is a neutralization reaction, which produces water plus a salt. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Answer only. Figure \(\PageIndex{1}\) The Reaction of Dilute Aqueous HCl with a Solution of Na2CO3 Note the vigorous formation of gaseous CO2. By solving an equation, we can find the value of . Acidbase reactions are essential in both biochemistry and industrial chemistry. In contrast, a base was any substance that had a bitter taste, felt slippery to the touch, and caused color changes in plant dyes that differed diametrically from the changes caused by acids (e.g., turning red litmus paper blue). Classify each compound as a strong acid, a weak acid, a strong base, or a weak base in aqueous solution. Acid-base reactions are essential in both biochemistry and industrial chemistry. (a chemical reaction in which an acid and a base react in stoichiometric amounts to produce water and a salt), (the general term for any ionic substance that does not have, logarithmic scale used to express the hydrogen ion (H. solution in which the total positive charge from all the cations is matched by an identical total negative charge from all the anions. Exercise \(\PageIndex{1}\): Acid Strength, The Arrhenius Definition of Acids and Bases, The BrnstedLowry Definition of Acids and Bases, Definition of Strong/Weak Acids & Bases, YouTube (opens in new window), status page at https://status.libretexts.org. The other product is water. Example 1: Simple formation of table salt that is NaCl is the most relevant example of neutralization between strong acid and strong base. Although the general properties of acids and bases have been known for more than a thousand years, the definitions of acid and base have changed dramatically as scientists have learned more about them. Weak acid equilibrium. The concentration of hydrogen ions in pure water is only 1.0 107 M at 25C. Asked for: balanced chemical equation and whether the reaction will go to completion. The most common strong bases are ionic compounds that contain the hydroxide ion as the anion; three examples are NaOH, KOH, and Ca(OH)2. Decide mathematic problems. To relate KOH to NaH2PO4 a balanced equation must be used. Mathematics is a way of dealing with tasks that involves numbers and equations. of the acid H2O. \(2CH_3CO_2Na(s) + H_2SO_4(aq) \rightarrow Na_2SO_4(aq) + 2CH_3CO_2H(aq)\). We're here for you 24/7. it . Typically less than 5% of a weak electrolyte dissociates into ions in solution, whereas more than 95% is present in undissociated form. The reaction of an acid and a base is called a neutralization reaction. Thus \([H^+] = 10^{-3.80} = 1.6 \times 10^{-4}\: M\). Recall that all polyprotic acids except H2SO4 are weak acids. According to the Arrhenius definition, an acid is a substance like hydrochloric acid that dissolves in water to produce H+ ions (protons; Equation \(\ref{4.3.1}\)), and a base is a substance like sodium hydroxide that dissolves in water to produce hydroxide (OH) ions (Equation \(\ref{4.3.2}\)): \[ \underset{an\: Arrhenius\: acid}{HCl_{(g)}} \xrightarrow {H_2 O_{(l)}} H^+_{(aq)} + Cl^-_{(aq)} \label{4.3.1} \], \[ \underset{an\: Arrhenius\: base}{NaOH_{(s)}} \xrightarrow {H_2O_{(l)}} Na^+_{(aq)} + OH^-_{(aq)} \label{4.3.2} \]. The reaction is then said to be in equilibrium (the point at which the rates of the forward and reverse reactions become the same, so that the net composition of the system no longer changes with time). Thus all acidbase reactions actually involve two conjugate acidbase pairsAn acid and a base that differ by only one hydrogen ion. Identify the acid and the base in this reaction. In ancient times, an acid was any substance that had a sour taste (e.g., vinegar or lemon juice), caused consistent color changes in dyes derived from plants (e.g., turning blue litmus paper red), reacted with certain metals to produce hydrogen gas and a solution of a salt containing a metal cation, and dissolved carbonate salts such as limestone (CaCO3) with the evolution of carbon dioxide. Example 1# HBr (acid) + KOH (base) KBr (salt) + H 2 O Example 2# HCl (acid)+ NaHCO 3 (base) NaCl (salt) + H 2 CO 3 Example 3# (Neutralizing all of the stomach acid is not desirable because that would completely shut down digestion. Stomach acid. The same term can be applied to alkaline solutions; thus, in 0.1 molar sodium hydroxide [OH ] = 0.1, [H 3 O +] = Kw / [OH ] = 1 10 14 /0.1 = 10 13, and pH = 13.0. Although Arrheniuss ideas were widely accepted, his definition of acids and bases had two major limitations: \[NH_{3\;(g)} + HCl_{(g)} \rightarrow NH_4Cl_{(s)} \label{4.3.3} \]. Describe how you would prepare 500 mL of a 1.00 M stock solution of HCl from an HCl solution that is 12.11 M. Using your stock solution, how would you prepare 500 mL of a solution that is 0.012 M in HCl? In contrast, only a fraction of the molecules of weak acids (An acid in which only a fraction of the molecules react with water) to producee \(H^+\) and the corresponding anion. Given the following salts, identify the acid and the base in the neutralization reactions and then write the complete ionic equation: What is the hydrogen ion concentration of each substance in the indicated pH range? 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. Using the balanced chemical equation for the acid dissociation reaction and Equation \(\PageIndex{24}\) or \(\PageIndex{25}\), determine [H+] and convert it to pH or vice versa. Strong acids and strong bases are both strong electrolytes. Although acetic acid is very soluble in water, almost all of the acetic acid in solution exists in the form of neutral molecules (less than 1% dissociates). One was proposed independently in 1923 by the Danish chemist J. N. Brnsted (18791947) and the British chemist T. M. Lowry (18741936), who defined acidbase reactions in terms of the transfer of a proton (H+ ion) from one substance to another. Definition of Strong/Weak Acids & Bases: Definition of Strong/Weak Acids & Bases, YouTube (opens in new window) [Definition of Strong] [Definition of Strong] [youtu.be] (opens in new window). For example, aspirin is an acid (acetylsalicylic acid), and antacids are bases. What other base might be used instead of NaOH? These reactions are exothermic. An acid-base reaction is a chemical reaction that occurs between an acid and a base.It can be used to determine pH.Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid-base theories, for example, Brnsted-Lowry acid-base theory. If organic, identify the compound as a weak base or a weak acid by the presence of an amine or a carboxylic acid group, respectively. Acidbase reactions are essential in both biochemistry and industrial chemistry. Over time, the reaction reaches a state in which the concentration of each species in solution remains constant. One of the key factors affecting reactions that occur in dilute solutions of acids and bases is the concentration of H+ and OH ions. In chemical equations such as these, a double arrow is used to indicate that both the forward and reverse reactions occur simultaneously, so the forward reaction does not go to completion. The foods and consumer products we encounter daily represent a wide range of pH values, as shown in Figure 8.7.2. Because isolated protons are very unstable and hence very reactive, an acid never simply loses an H+ ion. Because weak acids do not dissociate completely in aqueous solution, a more complex procedure is needed to calculate the pH of their solutions. The most common strong bases are ionic compounds that contain the hydroxide ion as the anion; three examples are NaOH, KOH, and Ca(OH)2. If the acid and base are equimolar, the . . The acid is hydroiodic acid, and the base is cesium hydroxide. If organic, identify the compound as a weak base or a weak acid by the presence of an amine or a carboxylic acid group, respectively. H + ( aq) + OH - ( aq ) H 2 O ( l) Acid and bases that ionize completely giving larger hydrogen or hydroxide ions in solutions are called strong acids and bases. The first person to define acids and bases in detail was the Swedish chemist Svante Arrhenius (18591927; Nobel Prize in Chemistry, 1903). Common weak acids include HCN, H2S, HF, oxoacids such as HNO2 and HClO, and carboxylic acids such as acetic acid. The pH of a solution is the negative logarithm of the H+ ion concentration and typically ranges from 0 for strongly acidic solutions to 14 for strongly basic ones. The strengths of the acid and the base generally determine whether the reaction goes to completion. Acid Base Neutralization Reactions & Net Ionic Equations Example: Writing a Molecular Equation for a Neutralisation Reaction. Conversely, strong bases react completely with water to produce the hydroxide ion, whereas weak bases react only partially with water to form hydroxide ions.
Urine Smells Like Cat Pee Ketosis,
Tiktok Unblocked 66,
Articles A