[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-343378-105":3,"detail-sidebar-cat-0-en-105":81,"doc-detail-343378-en":131},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","acid-base-equilibria-chapter-15-acid-base-equilibria","Acid-Base Equilibria - Chapter 15 - Acid-Base Equilibria","","Chapter 15 explains acid-base equilibria, focusing on common-ion effects and the resulting shifts in H+ or OH− concentrations. It develops equilibrium calculations, then treats buffered solutions as systems that resist pH change through the presence of a weak acid–conjugate base pair or a weak base–conjugate acid pair. The chapter covers buffer capacity, optimal preparation conditions, and how pH depends on concentration ratios, including use of the Henderson–Hasselbalch equation. It concludes with titration concepts and pH curve behavior for strong/weak acid-base systems.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/exam/","Exam",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/acid-base-equilibria-chapter-15-acid-base-equilibria/343378/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/acid-base-equilibria-chapter-15-acid-base-equilibria/343378.png","ImageObject",300,407,{"name":42,"@type":43},"Himbo","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-25","2026-09-22",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",13,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"How does the common-ion effect change equilibrium in acid or base solutions?","Question",{"text":63,"@type":64},"Adding a salt that supplies the common ion shifts equilibrium away from or toward the direction that reduces the effect, changing the concentrations of H+ or OH−. This directly alters the observed pH compared with expectations without the added common ion.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"What defines a buffered solution and what kinds of buffer systems are used?",{"text":68,"@type":64},"A buffered solution resists pH change when protons or hydroxide ions are added. It contains either a weak acid with its salt or a weak base with its salt, allowing added acid/base to be neutralized by the conjugate species.",{"name":70,"@type":61,"acceptedAnswer":71},"How is buffer capacity determined and how do you prepare an effective buffer?",{"text":72,"@type":64},"Buffer capacity is the amount of added protons or hydroxide ions the buffer can absorb without a significant pH change. Effective buffering occurs when the weak acid and conjugate base concentrations are comparable, and the pKa should be close to the desired pH.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},343378,1790701097,{"code":4,"msg":82,"data":83},"success",[84,88,92,95,100,105,110,115,120,123,127],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":93,"slug":94},70,"exam",{"id":96,"doc_module":4,"doc_module_name":25,"category_name":97,"show_sort_weight":98,"slug":99},5,"Comic",60,"comic",{"id":101,"doc_module":4,"doc_module_name":25,"category_name":102,"show_sort_weight":103,"slug":104},6,"Technology",50,"technology",{"id":106,"doc_module":4,"doc_module_name":25,"category_name":107,"show_sort_weight":108,"slug":109},7,"Healthcare",40,"healthcare",{"id":111,"doc_module":4,"doc_module_name":25,"category_name":112,"show_sort_weight":113,"slug":114},8,"Research & Report",30,"research-report",{"id":116,"doc_module":4,"doc_module_name":25,"category_name":117,"show_sort_weight":118,"slug":119},9,"Religion & Spirituality",20,"religion-spirituality",{"id":118,"doc_module":4,"doc_module_name":25,"category_name":121,"show_sort_weight":118,"slug":122},"World Cup","world-cup",{"id":124,"doc_module":4,"doc_module_name":25,"category_name":125,"show_sort_weight":124,"slug":126},10,"Lifestyle","lifestyle",{"id":128,"doc_module":4,"doc_module_name":25,"category_name":129,"show_sort_weight":96,"slug":130},19,"General","general",{"code":4,"msg":82,"data":132},{"doc_id":79,"user_id":133,"nickname":42,"user_avatar":134,"doc_module":4,"category_id":33,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":135,"file_id":136,"file_url":137,"file_type":138,"file_size":139,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":101,"language":140,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":12,"update_tm":144,"read_time":145,"preview_page_count":4},687197100911,"https://ap-avatar.wpscdn.com/avatar/a000239b6f1da00475?x-image-process=image/resize,m_fixed,w_180,h_180&k=1785132997149421697","Chapter 15 – Acid-Base Equilibria  \nAcid-Base Equilibria  \n15.1 Solutions of Acids or Bases Containing a Common Ion  \nA. Common Ion  \n1. Ion provided in solution by an aqueous acid (or base) as well as a salt  \na. HF(aq) and NaF (F- in common)  \nHF(aq) ⇆ H+(aq) + F- (aq) Excess F- added by NaF  \nEquilibrium shifts away from added  \ncomponent. Fewer H+ ions present.  \npH is higher than expected.  \nb. NH4OH and NH4Cl (NH4+ in common)  \nNH3(aq) + H2O(l) ⇆ NH4+(aq) +  OH- (aq)  \nEquilibrium shifts to the left. pH of the solution  \ndecreases due to a decrease in OH- concentration  \nB. Equilibrium Calculations  \n1. Consider initial concentration of ion from salt when calculating values for H+ and OH-  \n15.2 Buffered Solutions  \nA. Buffered Solution  \n1. A solution that resists a change in pH when either hydroxide ions or protons are added.  \n2. Buffered solutions contain either:  \na. A weak acid and its salt  \nb. A weak base and its salt  \nB. Calculations Involving Buffered Solutions Containing Weak Acids  \n1. \"Buffered solutions are simply solutions of weak acids or bases containing a common ion. The pH calculations on buffered solutions require exactly the same procedures introduced in Chapter 14. This is not a new type of problem.\"  \n2. \"When a strong acid or base is added to a buffered solution, it is best to deal with the stoichiometry of the resulting reaction first. After the stoichiometric calculations are completed, then consider the equilibrium calculations. This procedure can be presented as follows:  \nC. Buffering: How Does it Work?  \n1. OH- + HA 􀃆 A- + H2O  \nweak conjugate  \nacid base  \nOH- ions are not allowed to accumulate but are replaced by A- ions  \n[H + ][ A − ] + [HA]  \n2. Ka =  [HA]  [H ] = Ka  [ A − ]  \na. If the amounts of HA and A- originally present are very large compared with the amount of OH- added, the change in [HA]/[A-] will be small. Therefore the pH change will be small  \n3. Buffering also works for addition of protons instead of hydroxide ions  \nH+ + A- 􀃆 HA Conjugate Weak  \nBase acid  \nD. The Henderson-Hasselbalch Equation  \n1. pH = pKa + log􀂧􀂩􀂨 [[A−HA]] 􀂷􀂹􀂸 = pKa + log􀂧􀂩􀂨 [[baseacid]] 􀂷􀂹􀂸  \na. For a particular buffering system (acid-conjugate base pair), all solutions that have the same ratio [A-]/[HA] will have the same pH  \nE. Buffering with a Weak Base and Its Conjugate Acid  \n1. Weak base B reacts with any H+ added  \nB + H+ 􀃆 BH+  \nBase Conjugate  \nacid  \n2. Conjugate acid BH+ reacts with any added OH  \nBH+ + OH- 􀃆 B + H2O  \nConjugate Base  \nAcid  \nF. Summary  \n1. Buffered solutions contain relatively large concentrations of a weak acid and the corresponding weak base. They can involve a weak acid HA and the conjugate base A- or a weak base and the conjugate acid BH+  \n2. When H+ is added to a buffered solution, it reacts essentially to completion with the weak base present  \n3. When OH- is added to a buffered solution, it reacts essentially to completion with the weak acid present  \n4. The pH in the buffered solution is determined by the ratio of the concentrations of the weak acid and the weak base. The pH remains relatively unchanged as long as the concentrations of buffering materials are large compared with the amounts of H+ or OH- added  \n15.3 Buffer Capacity  \nA. Buffering Capacity  \n1. The amount of protons or hydroxide ions the buffer can absorb without a significant change in pH.  \na. The pH of a buffered solution is determined by the ratio [A-]/[HA]  \nb. The capacity of a buffered solution is determined by the magnitudes of [HA] and [A-]  \nB. Preparing a Buffer  \n1. Optimal buffering occurs when [HA] is equal to [A-] ([A-]/[HA] = 1 )  \n2. The pKa of the weak acid to be used should be as close as possible to the desired pH  \n\n| Table 15.1 Change in [C2 H3O2-]/[HC2 H3O2] for two solutions when 0.01 mol H+ is added to 1.0 L of each |  |  |  |  |\n| --- | --- | --- | --- | --- |\n| Solution | 􀂧􀂨  [C2 H3 O2 − ] 􀂷􀂸􀂩􀂨 [HC2 H3 O2 ] 􀂹􀂸 orig | 􀂧􀂨  [C2 H3 O2 − ] 􀂷􀂸􀂩􀂨 [HC2 H3 O2 ] 􀂹􀂸 new | Change","cbCaicchOgZ9679X","https://ap.wps.com/l/cbCaicchOgZ9679X","pdf",138821,"English","# Chapter 15 – Acid-Base Equilibria\n## 15.1 Solutions of Acids or Bases Containing a Common Ion\n## 15.2 Buffered Solutions\n## 15.3 Buffer Capacity\n## 15.4 Titration and pH Curves","[{\"question\":\"How does the common-ion effect change equilibrium in acid or base solutions?\",\"answer\":\"Adding a salt that supplies the common ion shifts equilibrium away from or toward the direction that reduces the effect, changing the concentrations of H+ or OH−. This directly alters the observed pH compared with expectations without the added common ion.\"},{\"question\":\"What defines a buffered solution and what kinds of buffer systems are used?\",\"answer\":\"A buffered solution resists pH change when protons or hydroxide ions are added. It contains either a weak acid with its salt or a weak base with its salt, allowing added acid/base to be neutralized by the conjugate species.\"},{\"question\":\"How is buffer capacity determined and how do you prepare an effective buffer?\",\"answer\":\"Buffer capacity is the amount of added protons or hydroxide ions the buffer can absorb without a significant pH change. Effective buffering occurs when the weak acid and conjugate base concentrations are comparable, and the pKa should be close to the desired pH.\"}]","Acid-Base Equilibria - Chapter 15 - Acid-Base Equilibria | PDF",1790050968,15]