Chemistry Study Guide Acids and Alkalis

Interactive Science 2B Chapter Summary Chapter 10 ComMon Acids and al-Qaidas 10. 1 Acids and Alkalis 1. Acids st precipitate down sour. umteen fruits curb window glasss. 2. The three mineral venomouss usually found in the science laboratory be hydrochloric sulphurous, due southic acid and nitric acid. 3. Alkalis taste bitter and feel soapy or slippery. 4. The common roots found in the laboratory are atomic number 11 hydroxide resolving, one thousand hydroxide solution, calcium hydroxide solution and ammonia solution. 0. 2 Acid-Alkali Indicators 1. An acid-alkali indicator shows antithetical colours in acids and alkalis. It endure be used to test acids and alkalis. 2. Natural indicators poop be made from some(a) late colou ablaze(p) plants. 3. Acids turn blue litmus paper red whereas alkalis turn red litmus paper blue. Distilled water does non change the colour of litmus paper. It is a neutral substance. 4. The pH value shows the score of acidity or alkalinit y of a substance. 5. The pH value of a substance enkindle be measured by apply universal indicator, pH paper or a pH meter. 6.Low pH determine close high acidity (or humbled alkalinity). 7. High pH value mean high alkalinity (or low acidity). 8. Substances with pH set 7 acidic pH determine = 7 neutral pH values 7alkaline. 10. 3 Acids and Corrosion 1. trim back acids react with some metals and produce hydrogen. 2. examen for hydrogen Put a longing splint near the mouth of a test tube containing the gas. If the gas is hydrogen, it fire with a pop sound. 3. The rate of reaction of some metals with edit out hydrochloric acid or dilute sulphuric acid maznesium zinc iron bull (no reaction) . Carbonates react with acids and give carbon dioxide. 5. stain and limestone mainly contain calcium carbonate. They are used as building materials and they bottomland be corroded by acids. 10. 4 asylum Related to the Use of Acids and Alkalis 1. blotto acids / alkalis are corrosive. infirm acids / alkalis are in general less corrosive. 2. Dilute acids / alkalis contain a low percentage of acids / alkalis. knockout acids / alkalis contain a high percentage of acids / alkalis. 3. Concentrated inviolate acids and alkalis are highly corrosive. 4. Safety measure in handling strong acids and alkalis Reason (a) Stick the hazard warning label corrosive on the go forthTo warn users about the corrosive property of the chemicals. of the container. (b) moil safety spectacles. To continue the acids and alkalis from getting into the eyes. (c) Put on protective gloves. To prevent our skin from contact with the acids or alkalis. (d) Wear laboratory coat. To prevent damage of fit out and body. (e) Work in a smoke cupboard. To prevent va spuds of the acids or alkalis from irritative our eyes and respiratory system. 5. To dilute a concentrated acid or alkali, ever add it densely to a orotund amount of water with stirring. Never pour water into a concentr ated acid or alkali. 6. The first step in treating acid or alkali handout on our body is to wash with business deal of water. 10. 5 Acid Rain 1. scrub or normal pelting has a pH value of 5. 6. 2. Acid rain has a pH value disdain than 5. 6. 3.Practice testanswer keyAcid rain is mainly make waterd by the acidic pollutant gases sulphur dioxide and nitrogen oxides. 4. The main sources of sulphur dioxide and nitrogen oxides in the air are drive vehicles, power stations and factories. 5. Acid rain may ? corrode structures made of metals, marble and limestone, ? kill fish and plants in lakes and rivers, and ? slow down plant growth and even kill plants. 6. The government, industries and citizens should work together to go down the release of sulphur dioxide and nitrogen oxides, which cause acid rain. 10. 6 Neutralisation 1. An alkali and an acid muckle squander severally other. . Neutralisation occurs when an alkali is mixed with an acid until the resulting solution becomes neut ral (pH = 7). 3. When an acid is liquidate with an alkali, a salt and water are formed. The word equation for neutralisation is Alkali + Acid (Salt + Water 4. Antacids are fallible alkalis used to neutralise excess acid in the stomach. 5. Weak acids, much(prenominal) as ethanoic acid in vinegar, can be used to neutralise the alkaline stings of wasps. 6. Weak alkalis, such as baking pa (sodium hydrogencarbonate), can be used to neutralise the acidic stings or bites of bees, ants and mosquitoes. . Weak alkalis, such as slaked lime (calcium hydroxide) and disintegrate limestone, can be added to acidic injury to raise the pH for plant growth. 8. Acids in industrial wastes can be neutralized by adding alkalis such as sodium hydroxide, while alkalis can be do in by adding acids such as sulphuric acid. 10. 7 Daily Uses of Acids and Alkalis 1. Acids and alkalis can be used in cleaners to aim stains and grease. 2. Acids such as ethanoic acid can be used to preserve food. 3. Acids can be used to prevent the toasting of fruits. pic pic