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Descrição
FlashCards por gfhgfhg gfhgfhg, atualizado more than 1 year ago
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Criado por gfhgfhg gfhgfhg
aproximadamente 9 anos atrás
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| Questão | Responda |
| what is an exothermic reaction and give examples and uses | An exothermic reaction is one that transfers energy to the surroundings. Examples : combustion, many oxidation reactions, neutralisation. Everyday uses : self-heating cans, hand warmers. |
| what is an endothermic reaction and give examples and uses | An endothermic reaction is one that takes in energy from the surroundings. Examples: thermal decompositions. Uses: Some sports injury packs |
| Write the equation for the reversible reaction of hydrated copper sulfate to anhydrous copper sulfate indicating which directions are endo and exothermic and the colour change involved | |
| Soluble salts can be made by reacting acids with what 3 things ? | 1. metals – some are too reactive and others are not reactive enough 2. insoluble bases – the base is added to the acid until no more will react and the excess solid is filtered off 3. alkalis – an indicator can be used to show when the acid and alkali have completely reacted |
| Describe how nsoluble salts can be made | Insoluble salts can be made by mixing appropriate solutions of ions so that a precipitate is formed. |
| Give an important use of a precipitation reaction | Precipitation can be used to remove unwanted ions from solutions, for example in treating water for drinking or in treating effluent. |
| State 2 things that are bases. State something that is an alkalis. | Metal oxides and hydroxides are bases. Soluble hydroxides are called alkalis. |
| Describe what happens when you dissolve ammonia in water and give the importance of this | Ammonia dissolves in water to produce an alkaline solution. It is used to produce ammonium salts. Ammonium salts are important as fertilisers. |
| State which ions make something acid and which make it alkaline | Hydrogen ions, H+(aq), make solutions acidic Hydroxide ions, OH–(aq), make solutions alkaline. |
| what is the pH scale ? | The pH scale is a measure of the acidity or alkalinity of a solution. |
| Describe neutralisation in terms of the ions involved | In neutralisation reactions, hydrogen ions react with hydroxide ions to produce water. This reaction can be represented by the equation: H+(aq) + OH–(aq) ➞ H2O(l) |
| Give the equations for making the following soluble salts from soluble bases (alkalis) : sodium chloride from NaOH(aq) + HCl(aq) sodium sulphate from 2NaOH(aq) + H2SO4(aq) potassium sulphate from 2KOH(aq) + H2SO4(aq) | NaOH(aq) + HCl(aq) ==> NaCl(aq) + H2O(l) 2NaOH(aq) + H2SO4(aq) ==> Na2SO4(aq) + 2H2O(l) 2KOH(aq) + H2SO4(aq) ==> K2SO4(aq) + 2H2O(l) |
| Give the equations for making the following soluble salts from soluble bases (alkalis) : sodium nitrate from NaOH(aq) + HNO3(aq) ammonium nitrate from NH3(aq) +HNO3(aq) | NaOH(aq) + HNO3(aq) ==> NaNO3(aq) + 2H2O(l) NH3(aq) + HNO3(aq) ==> NH4NO3(aq) |
| What is the general word equation for the reaction of an acid with a metal | Acid + metal = salt (soluble) + hydrogen |
| What is the general word equation for the reaction of an acid with an alkali or base | Acid + alkali/base = salt + water |
| What is the general word equation for the reaction of an acid with a metal carbonate | acid + metal carbonate = salt (soluble) + water + carbon dioxide |
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