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Buffer in Solutions

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الكلية كلية الطب     القسم الكيمياء الحياتية     المرحلة 1
أستاذ المادة علاء جعفر محراث الشياش       07/01/2018 11:17:59
Buffer
Objective : Describe the role of buffers in maintaining the pH of a solution.

The pH of water and most solutions changes drastically when a small amount of acid or base is added. However, when an acid or base is added to a buffer solution, there is little change in pH. A buffer solution maintains pH by neutralizing small amounts of added acid or base. For example, blood contains buffers that maintain a consistent pH of about 7.4. If the pH of the blood goes slightly above or below 7.4, changes in oxygen levels and metabolic processes can be drastic enough to cause death. Even though we obtain acids and bases from foods and cellular reactions, the buffers in the body absorb those compounds so effectively that the pH of the blood remains essentially unchanged .

In a buffer, an acid must be present to react with any OH" that is added, and a base must be available to react with any added H3O+. However, that acid and base must not neutralize each other. Therefore, a combination of an acid-base conjugate pair is used to prepare a buffer. Most buffer solutions consist of nearly equal concentrations of a weak acid and a salt containing its conjugate base (see Figure 2). Buffers may also contain a weak base and a salt containing its conjugate acid.

المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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