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An acid—base reaction is a chemical reaction that occurs between an acid and a base. It can be used to determine pH.
Chapter 12 — Acid-Base Chemistry Introduction The terms acid and base have been used for several hundred years. Acids were substances that had a sour taste, were corrosive, and reacted with substances called bases. Substances that had a bitter taste, made skin slippery on contact, and reacted with acids were called bases. However, these simple definitions had to be refined as the chemical properties of acids and bases became better understood. The first chemical definition of acids and bases was made by Svante Arrhenius. In this theory, an acid ionizes in water much as an ionic substance, and the equilibrium constant for the reaction is called the acid ionization constant.
10.1: Introduction to Acids and Bases
Acids and bases have been known for a long time. When Robert Boyle characterized them in , he noted that acids dissolve many substances, change the color of certain natural dyes for example, they change litmus from blue to red , and lose these characteristic properties after coming into contact with alkalis bases. In the eighteenth century, it was recognized that acids have a sour taste, react with limestone to liberate a gaseous substance now known to be CO 2 , and interact with alkalis to form neutral substances. In , Humphry Davy contributed greatly to the development of the modern acid-base concept by demonstrating that hydrogen is the essential constituent of acids. Around that same time, Joseph Louis Gay-Lussac concluded that acids are substances that can neutralize bases and that these two classes of substances can be defined only in terms of each other. The significance of hydrogen was reemphasized in when Carl Axel Arrhenius defined an acid as a compound that dissolves in water to yield hydrogen cations now recognized to be hydronium ions and a base as a compound that dissolves in water to yield hydroxide anions. Acids and bases are common solutions that exist everywhere.
Make sure you thoroughly understand the following essential ideas which have been presented above. The concepts of an acid, a base, and a salt are very old ones that have undergone several major refinements as chemical science has evolved. Our treatment of the subject at this stage will be mainly conceptual and qualitative, emphasizing the definitions and fundamental ideas associated with acids and bases. We will not cover calculations involving acid-base equilibria in these lessons. Some early writers suggested that acidic molecules might have sharp corners or spine-like projections that irritate the tongue or skin. Acids have long been recognized as a distinctive class of compounds whose aqueous solutions exhibit the following properties:. Litmus is a natural dye found in certain lichens.
Basically, acid-base reactions are chemical reactions with transfer of hydrogen cations protons. However, there are several concepts according to which acid-base reactions are defined differently. The terms pH value , acid-base titration , chemical equilibrium , stoichiometry and others are closely related to the topic. The following list shows available online information on the individual acid-base reactions, models and concepts. Acids and Bases An introduction.
Chapter 12 – Acid-Base Chemistry
И все же… секрет Цифровой крепости будет служить Хейлу единственной гарантией, и он, быть может, будет вести себя благоразумно. Как бы там ни было, Стратмор знал, что Хейла можно будет всегда ликвидировать в случае необходимости. - Решайтесь, приятель! - с издевкой в голосе сказал Хейл. - Мы уходим или нет? - Его руки клещами сжимали горло Сьюзан.
The Arrhenius Definition of Acids and Bases
ВСЯ ХИТРОСТЬ В МЕНЯЮЩЕЙСЯ ПОСЛЕДОВАТЕЛЬНОСТИ. В это трудно было поверить, но она видела эти строки своими глазами. Электронная почта от Энсея Танкадо, адресованная Грегу Хейлу. Они работали. Сьюзан буквально онемела, когда эта страшная правда дошла до ее сознания.
Росио уверенно, по-хозяйски вошла в спальню. - Чем могу помочь? - спросила она на гортанном английском. Беккер не мигая смотрел на эту восхитительную женщину. - Мне нужно кольцо, - холодно сказал. - Кто вы такой? - потребовала .