Category: Ch 2 – Acids, Bases and Salts
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Plaster of paris
Plaster of Paris is a widely used chemical compound that is extensively used in sculpting materials and gauze bandages. Plaster of Paris is a white powdery chemical compound that is hydrated calcium sulphate that is usually obtained by calcining gypsum. While we have seen many applications of this material in our everyday lives, if we…
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Bleaching powder
Bleaching powder is soluble in water and is used as a bleaching agent in textile industries. It is also used as an oxidizing agent and a disinfectant in many industries. It should also be noted that bleaching powder is synthesized by the reacting chlorine gas on dry slaked lime i.e. Ca(OH)2. Chemical formula – Ca(OCl)Cl…
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Salts
Salts A salt is a combination of an anion of an acid and a cation of a base. Examples – KCl, NaNO3 ,CaSO4, etc. Salts are usually prepared by the neutralisation reaction of an acid and a base. Common salt Sodium Chloride (NaCl) is referred to as common salt because it’s used all over the world for…
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Manufacture of Acids and Bases
Manufacture of acids and bases a) Nonmetal oxide + water → acid SO2(g) + H2O(l) → H2SO3(aq)SO3(g) + H2O(l) → H2SO4(aq)4NO2(g) + 2H2O(l) + O2(g) → 4HNO3(aq) Non-metal oxides are thus referred to as acid anhydrides. b) Hydrogen + halogen → acid H2(g) + Cl2(g) → 2HCl(g)HCl(g) + H2O(l) → HCl(aq) c) Metallic salt + conc. sulphuric acid…
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Universal indicator
A universal indicator has a pH range from 0 to 14 that indicates the acidity or alkalinity of a solution.A neutral solution has pH=7 pH pH=−log10[H+]In pure water, [H+]=[OH−]=10−7 mol/L. Hence, the pH of pure water is 7.The pH scale ranges from 0 to 14.If pH < 7 → acidic solutionIf pH > 7→ basic solution pH scale Importance…
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Strength of acids and bases
Strong acid or base: When all molecules of a given amount of an acid or a base dissociate completely in water to furnish their respective ions, H+(aq) for acid and OH−(aq) for base).Weak acid or base: When only a few of the molecules of a given amount of an acid or a base dissociate in water to…
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Diff. b\w a base and an alkali
Base: Bases undergo neutralisation reaction with acids. They are comprised of metal oxides, metal hydroxides, metal carbonates and metal bicarbonates. Most of them are insoluble in water. Alkali: An alkali is an aqueous solution of a base, (mainly metallic hydroxides). It dissolves in water and dissociates to give OH− ion. All alkalis are bases, but not…
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Acid-Base Reactions
A neutralisation reaction occurs when an acid reacts with a base. A salt and water are the end products of this reaction. An acid–base neutralisation reaction is formulated as a double-replacement reaction in this standard approach. Reactions of acids and bases a) Reaction of acids and bases with metals Acids, in general, react with metals…
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Physical test
Given are two possible physical tests to identify an acid or a base. a. Taste An acid tastes sour whereas a base tastes bitter.The method of taste is not advised as an acid or a base could be contaminated or corrosive. Example: The flavours of curd, lemon juice, orange juice, and vinegar are all sour. Because…
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Acid and Base
Ionisable and non-ionisable compounds An ionisable compound when dissolved in water or in its molten state, dissociates into ions almost entirely. Example: NaCl, HCl, KOH, etc.A non-ionisable compound does not dissociate into ions when dissolved in water or in its molten state. Example: glucose, acetone, etc. Acids and Bases An acid is any hydrogen-containing substance that is…