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Part 1 Revision Helper 溫習錦囊 (Bilingual version) 雙語版本部分 Revision notes 溫習筆記第 Chapter 1 第 20 28 章 Air Common and burning acids and alkalis 常見的酸和鹼 28.1 Common acids 28.

The figure below shows some examples of drinks, foods and seasonings that contain acids.

1 Part 1 Revision Helper 溫習錦囊 (Bilingual version) 雙語版本部分 Revision notes 溫習筆記第 Chapter 1 第章 Air Common and burning acids and alkalis 常見的酸和鹼 28.1 Common acids 28.1 常見的酸 Q1 A1 What substances commonly found in daily life contain acids? Suggest some examples. 日常生活中有甚麼物品含有酸? 又有甚麼例子呢? Many drinks and foods that contain acids taste sour. The figure below shows some examples of drinks, foods and seasonings that contain acids. Soft drinks contain carbonic acid 汽水含有碳酸 Vinegar contains ethanoic acid 醋含有乙酸 Tea contains tannic acid 茶含有單寧酸日常生活中許多飲品和食品都含有酸, 它們都帶有酸味下圖展示一些含有酸的飲品食品和調味料的例子 Citrus fruits like grapefruit, lemon and orange contain citric acid and ascorbic acid (vitamin C) 西柚橙和檸檬等柑橘類水果含有檸檬酸和抗壞血酸 ( 丙種維生素 ) Spinach contains oxalic acid 菠菜含有草酸 Yoghurt contains lactic acid 乳酪含有乳酸 Grapes contain tartaric acid 提子含有酒石酸 Apples contain malic acid 蘋果含有蘋果酸 Besides, some personal care products, household cleaners and some drugs also contain acids. 另外, 許多個人護理產品家居清潔用品和某些藥物也含有酸 body lotion 潤膚露 hair conditioner 護髮素 toilet cleaner 廁所清潔劑 body shampoo 沐浴露 Aspirin 阿士匹靈 1

2 Q2 A2 What acids are commonly found in the laboratory? What should we pay attention to when handling these acids? 實驗室中最常用的酸有哪幾種? 當我們使用這些酸時, 應採取甚麼安全措施? The most common acids used in the laboratory are hydrochloric acid, sulphuric acid and nitric acid. All these acids are corrosive. There are hazard warning labels on the reagent bottles containing them. When using acids for experiments, we should never taste them. We must wear safety goggles and avoid any direct contact with acids when we handle them. 實驗室中最常用的酸包括氫氯酸氫氯酸硫酸和硝酸硝酸這些酸均具有腐蝕性, 因此盛載這些酸的試劑瓶都貼上危險警告標籤我們不可以把做實驗時使用的酸放進口中在處理酸時, 我們必須佩戴安全眼鏡, 並避免與酸直接接觸 Acids commonly used in a school laboratory 學校實驗室中常用的酸 28.2 Common alkalis 28.2 常見的鹼 Q3 A3 What substances commonly found in daily life contain alkalis? Suggest some examples. 日常生活中有甚麼物品含有鹼? 又有甚麼例子呢? Alkalis have a bitter taste and a slippery feel. They are commonly found in household cleaners such as glass cleaners, oven cleaners and drain cleaners. Many daily products such as soaps, alkaline batteries, baking soda and toothpaste also contain alkalis. 鹼帶有苦澀味, 觸摸時會給人一種滑溜的感覺許多家居清潔用品, 如玻璃清潔劑爐具清潔劑和通渠劑都含有鹼另外, 一些日常用品如肥皂鹼性電池梳打粉和牙膏等也含有鹼 Household cleaners and daily products that contain alkalis Understanding Integrated Science for the 21st Century (3rd Edition) 一些含有鹼的家居清潔用品和日常用品最新綜合科學邁進 21 世紀 ( 第三版 ) 2

3 Q4 A4 What alkalis are commonly found in the laboratory? What should we pay attention to when handling these alkalis? 驗室中最常用的鹼有哪幾種? 當我們使用這些鹼時, 應採取甚麼安全措施? The most common alkalis in the laboratory include sodium hydroxide, calcium hydroxide (lime water) and ammonia solution. Sodium hydroxide and ammonia solution are corrosive. We must wear safety goggles and avoid any direct contact with these alkalis when handling them. The vapour from ammonia solution is irritating. We should ensure good ventilation when handling ammonia solution. 實驗室中最常用的鹼包括氫氧化鈉氫氧化鈉氫氧化鈣 ( 即石灰水 ) 和氨溶液氨溶液氫氧化鈉和氨溶液都具有腐蝕性, 我們處理這些鹼時必須佩戴安全眼鏡, 並避免與它們直接接觸氨溶液會釋出具刺激性的氨蒸氣, 使用時應避免吸入, 並保持空氣流通 Alkalis commonly used in a school laboratory 學校實驗室中常用的鹼 3

4 28.3 Indicators for testing acids and alkalis 28.3 測試酸和鹼的指示劑 Q5 A5 What is natural indicator? Suggest some examples of natural indicators. 甚麼是天然指示劑? 又有甚麼例子呢? Some plants contain pigments which change colour when mixed with acids or alkalis. These plant pigments can be used as natural indicators to test for acids or alkalis. In the 17 th century, an Irish scientist, Robert Boyle succeeded in preparing indicators from different types of plants. Red cabbage leaves, Hibiscus petals, strawberries, blueberries and red roses can be used as natural indicators. These plants contain pigments which change colour when mixed with acids or alkalis. 有些植物所含的色素, 在酸性和鹼性環境下會呈現不同的顏色, 因此它們可用作天然指示劑, 以分辨酸和鹼在十七世紀, 愛爾蘭科學家波義耳便成功利用植物汁液製備天然指示劑紅色捲心菜大紅花花瓣草莓藍莓和紅玫瑰也可用作天然指示劑, 這些植物的汁液在酸性和鹼性環境下會呈現不同的顏色 Strawberry Blueberry Red rose 草莓藍莓紅玫瑰 4

5 Q6 A6 What indicators are commonly used in the laboratory to test for acids and alkalis? 實驗室中常用的指示劑有哪些? Litmus and universal indicator are indicators commonly used in the laboratory. 石蕊和通用指示劑通用指示劑是實驗室中常用的指示劑 1. Litmus 1. 石蕊 Litmus is a mixture of pigments extracted from 石蕊是從地衣中提取出來的色素混合 lichen. 物 Blue litmus is used to test for acidic solutions. It 藍色石蕊可用來測試酸性溶液酸性 changes to red in acidic solutions. 溶液可以使藍色石蕊變為紅色 Red litmus is used to test for alkaline solutions. 紅色石蕊可用來測試鹼性溶液鹼性 It changes to blue in alkaline solutions. 溶液可以使紅色石蕊變為藍色 Litmus is available in both solution form (litmus 石蕊可以製成溶液 ( 石蕊溶液 ), 亦可 solution) and paper form (litmus paper). 以製成試紙 ( 石蕊試紙 ) red litmus paper 紅色石蕊試紙 blue litmus paper 藍色石蕊試紙 5

6 A6 2. Universal indicator 2. 通用指示劑 Universal indicator is a mixture of several 通用指示劑是由多種指示劑混合而 indicators. 成 It shows a wide range of colours depending on 它會在不同酸度酸度或鹼度 ( 即酸鹼 the acidity or alkalinity of a solution. 度 ) 的溶液中呈現不同的顏色 It is used to indicate the degree of acidity and 它可用來測試物質的酸度和鹼度 alkalinity of a solution. It is available in both solution form (universal 它可以製成溶液 ( 通用指示劑溶 indicator solution) and paper form (ph paper) 液 ), 亦可以製成試紙 (ph 試紙 ) ph paper ph 試紙 There is a ph colour chart on the bottle storing universal indicator solution or the box storing ph paper. It shows a series of colours. Each colour on the chart corresponds to a ph value. The ph value is a number showing how acidic or alkaline a solution is. In general, the ph value ranges from 0 to 14. This range of ph values is known as the ph scale. 每一瓶通用指示劑溶液或每一盒 ph 試紙都附有 ph 顏色圖表, 顯示一系列的顏色, 圖表的每一種顏色對應於一個 ph 值 ph 值是一個數字, 用來顯示溶液的酸鹼度,pH 值的範圍一般是由 0 至 14, 這個範圍稱為 ph 標度 6

7 Q7 A7 What are the ph values of acidic, neutral and alkaline solutions? Suggest some examples for each kind of solutions. 酸性溶液中性溶液和鹼性溶液的 ph 值分別是多少? 每種溶液又有甚麼例子呢? An acidic solution has a ph value less than 7. The lower the ph value, the more acidic the solution is. An alkaline solution has a ph value greater than 7. The higher the ph value, the more alkaline the solution is. A neutral solution has a ph value of exactly 7. The figure below shows the ph scale and the ph values of some common substances. 酸性溶液的 ph 值低於 7,pH 值愈低表示酸度愈高鹼性溶液的 ph 值高於 7,pH 值愈高表示鹼度愈高既不屬酸性又不屬鹼性的溶液屬中性, 它們的 ph 值是 7 下圖展示 ph 標度及一些常見物質的 ph 值 hydrochloric acid 氫氯酸 orange juice 橙汁 distilled water glass cleaner drain cleaner 蒸餾水玻璃清潔劑通渠劑 ph value ph 值 neutral 中性 Cola black coffee detergent lime water 可樂黑咖啡洗潔精石灰水 high acidity low acidity low alkalinity high alkalinity 酸度高酸度低鹼度低鹼度高 7

8 Q8 A8 Universal indicator can only give a rough measurement of the ph value of a solution. What can we use to obtain a more accurate ph value of a solution? 通用指示劑只能粗略測試出溶液的 ph 值, 我們可利用甚麼儀器來更準確地量度溶液的 ph 值? We can use a ph meter to measure the ph value of a solution more accurately. The reading measured by the ph meter can be accurate to two decimal places. 我們可利用 ph 計來更準確地量度溶液的 ph 值 ph 計所量度的讀數可準確至小數點後兩個位 probe 探測器 ph value displayed ph 值 ph meter ph 計 8

9 Revision Helper 溫習錦囊 (Bilingual version) 雙語版本 Chapter 第 29 章 Acids and corrosion 酸和腐蝕 29.1 酸的腐蝕性質 29.1 Corrosive nature of acids 酸能否與金屬產生反應 Do acids react with metals? Q13 A13 Yes, acids react with some metals such as 酸會與某些金屬 (例如鎂鋁鐵和鋅) 產生反應它們均會被酸腐蝕腐蝕腐蝕 magnesium, aluminium, iron and zinc. These metals are corroded by acids. During the reactions, hydrogen is produced. 金屬與酸所產生的反應會釋出氫還會放出熱能我們可利用燃燒中的木條來測試氫當我們把燃燒中的木條放在盛有氫的試管管口時會聽到卜一聲 Heat is also given out. We can test for hydrogen using the burning splint test. When a burning splint is put near the mouth of the test tube containing hydrogen, a pop sound is heard. burning splint 燃燒中的木條 hydrogen 氫 Q10 Do acids react with building materials? 酸能否與建築材料產生反應 A10 Yes, acids react with calcium carbonate in some building materials such as marble and limestone. These building materials are corroded by acids. During the reaction, carbon dioxide is formed. 酸會與建築材料 (例如大理石大理石和大理石石灰石) 碳酸鈣產生反應這石灰石中的碳酸鈣碳酸鈣些建築材料會受到酸腐蝕酸與碳酸鈣所產生的反應會釋出二氧化碳 Understanding Integrated Science for the 21st Century (3rd Edition) 最新綜合科學邁進 21 世紀 (第三版) 9

10 29.2 Acid rain 29.2 酸雨 Q11 A11 What are the causes and effects of acid rain? 酸雨是怎樣形成的? 酸雨對環境造成甚麼影響? Burning fossils fuels produces sulphur dioxide and nitrogen oxides. Sulphur dioxide and nitrogen oxides react with water and oxygen in the atmosphere to form sulphuric acid and nitric acid respectively. These acids dissolve in rainwater to form acid rain. The effects of acid rain on the environment include corroding metal products and building materials, killing organisms living in water and damaging plants. The diagram below summarises the formation of acid rain and its effects on the environment. 燃燒化石燃料會釋出大量的二氧化硫和氮氧化物氮氧化物二氧化硫和氮氧化物會與大氣中的水和氧產生反應, 分別形成硫酸和硝酸硫酸和硝酸溶解在雨水中, 並形成酸雨酸雨酸雨對環境的影響包括腐蝕金屬製品和建築材料毒害水生生物及破壞林木下圖概括了酸雨的形成過程及酸雨對環境所造成的影響 1 acidic gases (e.g. sulphur dioxide and nitrogen oxides) released into the atmosphere 酸性氣體 ( 如二氧化硫和氮氧化物 ) 釋放到大氣中 2 acidic gases carried by the wind 酸性氣體隨風飄送 3 acidic gases dissolve in rainwater to form acid rain 酸性氣體溶解在雨水中, 形成酸雨 4 acid rain corrodes metal products and building materials, kills organisms living in water and damages plants 酸雨腐蝕金屬製品和建築材料毒害水生生物及破壞林木 10

11 Q12 What preventive measures can be done to help control acid rain? 甚麼措施可減少酸雨的形成? A12 The most effective way to control acid rain is to reduce the emission of air pollutants such as sulphur dioxide and nitrogen oxides. The government has taken a wide range of measures to reduce the emission of these air pollutants from vehicles and power stations. To be responsible citizens, we should use public transport and save electricity in order to help reduce the emission of air pollutants. 要有效減少酸雨的形成, 我們必須先減少空氣污染物 ( 如二氧化硫和氮氧化物 ) 的排放量香港特區政府近年已採取了多項措施, 以減少來自汽車和發電廠的空氣污染物排放量我們作為社會的一份子, 也應使用公共交通工具和節約能源, 以協助減少空氣污染物排放量 11

12 Chapter 第 Revision Helper 溫習錦囊 (Bilingual version) 雙語版本 30 章 Uses of acids, alkalis and neutralisation 酸鹼及中和作用的應用 30.1 Uses of acids and alkalis 30.1 酸和鹼的應用 Q13 A13 Why can acids be used as food preservatives? 為甚麼酸可作為食品防腐劑? Fresh food may spoil due to the action of micro-organisms. Most micro-organisms cannot grow and reproduce in an acidic medium. Foods can be preserved by soaking them in acids. Therefore, acids can be used as food preservatives. For example, vinegar (contains ethanoic acid) can be used to preserve cucumbers and scallions. We say that these foods are pickled with vinegar. 新鮮食物變壞主要是由微生物引起的酸性介質可以減慢微生物的生長和繁殖我們可以把食物浸在酸中來保存, 故此酸可作為食品防腐劑食品防腐劑例如, 白醋含有乙酸, 可用來保存青瓜和蕎頭 cucumber 青瓜 scallion 蕎頭 Foods preserved in vinegar 保存在白醋中的食物 12

13 Q14 A14 What is browning? Why can acids be used to prevent browning? 水果出現變褐的現象是甚麼意思? 為甚麼可用酸來防止水果變褐? Browning occurs in many fruits such as apples, bananas and pears. When these fruits are cut open and exposed to air, they turn brown. Enzymes inside the fruits can speed up the browning process. However, they can only function properly within a certain range of ph value. Therefore, the browning of fruits can be slowed down by putting them in environments with ph that the enzymes cannot function properly. 許多水果, 例如蘋果香蕉和梨都會出現變褐的現象這些水果切開並暴露於空氣中後會變褐水果內的酶會加速變褐的過程然而, 酶只有在特定的 ph 值範圍內才能發揮它的功能因此, 我們把水果置於酶不能正常發揮功能的 ph 環境中, 便可減慢水果變褐的過程 Q15 A15 Why can both acids and alkalis be used as household cleansing agents? Suggest some examples of acidic and alkaline household cleansing agents. 為甚麼酸和鹼可用作家居清潔劑? 有甚麼家居清潔劑含有酸或鹼? Household cleansing agents contain acids which can react with stains to form substances that are soluble in water The following are two household cleansing agents containing acids. 含有酸的家居清潔劑可跟頑固的污漬反應, 並產生可溶於水的物質下圖展示兩種含有酸的家居清潔劑 Toilet cleaner 廁所清潔劑 Rust remover 除銹劑 Toilet cleaner can be used to remove limescale (contains mainly calcium carbonate) in a toilet bowl. 廁所清潔劑可清除廁盆上的污垢 ( 主要含有碳酸鈣 ) A rust remover can be used to remove rust (oxides of iron) on an iron object. 除銹劑可清除鐵製品上的鐵銹 ( 鐵的氧化物 ) 13

14 A15 On the other hand, household cleansing agents contain alkalis which can react with greases to form substances that can be easily washed away by water. The following are three household cleansing agents containing alkalis. 另一方面, 含有鹼的家居清潔劑可與油脂反應, 所產生的物質可輕易用水沖走下圖展示三種含有鹼的家居清潔劑 Drain cleaner 通渠劑 Oven cleaner 爐具清潔劑 Drains cleaners that contain sodium hydroxide are commonly used to clear the grease from a drain. 含有氫氧化鈉的通渠劑常用來清理堵塞的渠道 Grease left on the oven surface can be removed by using an oven cleaner. 殘留在爐具上的油脂可使用爐具清潔劑來消除 Glass cleaner 玻璃清潔劑 Greasy films on the windows can be removed by using a glass cleaner. 玻璃窗上的油脂可使用玻璃清潔劑來清除 14

15 30.2 Uses of neutralisation 30.2 中和作用的應用 Q16 What is neutralisation? 甚麼是中和作用? A16 Acids and alkalis react with each other when they are mixed together. This reaction is called neutralisation. During neutralisation, the ph value of the solution changes. The point where the acid completely neutralises the alkali as shown by the colour change of the indicator can be regarded as the end-point. 當酸和鹼混合時, 它們會產生反應這種酸和鹼之間的化學反應稱為中和作用中和作用當酸和鹼混合時, 溶液的 ph 值會出現變化利用指示劑的顏色變化可測定酸和鹼剛好完全中和時的狀態, 此狀態可稱為終點終點 15

16 Q17 A17 What products are formed in neutralisation reaction? 中和作用會產生甚麼物質? When an acid neutralises an alkali (or vice versa), salt and water are formed, and heat is given out. Neutralisation can be represented by the following word equation. acid + alkali salt + water 酸和鹼發生中和作用時, 會生成鹽和水, 並釋出熱能中和作用可用以下文字方程式文字方程式表示 : 酸 + 鹼鹽 + 水 For example, hydrochloric acid reacts with sodium hydroxide to produce sodium chloride and water. The word equation of this reaction can be written as: hydrochloric acid + sodium hydroxide sodium chloride + water 例如, 氫氯酸與氫氧化鈉發生反應, 產生氯化鈉和水, 該反應的文字方程式可以寫成 : 氫氯酸 + 氫氧化鈉氯化鈉 + 水 We can also use chemical symbols to represent the above substances. The chemical symbols for hydrochloric acid, sodium hydroxide, sodium chloride and water are HCl, NaOH, NaCl and H 2 O respectively. Therefore, the reaction can be represented by the following equation: HCl + NaOH NaCl + H 2 O 以上的化學物質可以用化學符號化學符號來表示氫氯酸氫氧化鈉氯化鈉和水的化學符號分別是 HCl NaOH NaCl 和 H 2 O 因此, 這反應也可用以下方程式表示 : HCl + NaOH NaCl + H 2 O Sodium chloride is the table salt we add to our food for taste. 氯化鈉是我們日常食用的餐桌鹽 16

17 Q18 A18 What are the uses of neutralisation in daily life? 中和作用在日常生活中有甚麼應用? The following are some examples of common applications of neutralisation. 以下是中和作用常見的應用 1. Neutralisation of stomach acid 1. 中和胃酸 Antacids can be used to relieve stomach upset. Many 制酸劑可舒緩胃部不適許多制 antacids contain an alkali which can neutralise excess acid 酸劑都含有鹼, 可以用來中和過 in our stomach. 多胃酸 Antacid tablets of different brands 從藥房購買的不同制酸劑 2. Treatment of industrial waste containing acids and alkalis 2. 處理酸性和鹼性工業廢料 To reduce pollution, industrial waste should be treated 工業廢料在排放之前必須經過 before it is discharged. Alkalis (e.g. calcium hydroxide) can 處理, 以減少造成污染廢料 be used to neutralise acidic waste while acids (e.g. 中的酸可用適量的鹼 ( 例如氫 sulphuric acid) can be used to neutralise alkaline waste. 氧化鈣 ) 來中和 ; 而廢料中的鹼則可用適量的酸 ( 例如硫酸 ) 來中和 The Chemical Waste Treatment Centre at Tsing Yi is responsible for the collection, processing and final treatment of the chemical waste. 位於青衣的化學廢物處理中心專門負責收集和處理化學廢料 17

18 A18 3. Treatment of wasp, bee, mosquito and ant stings 3. 治療蟲螫 The stings of bees, ants and mosquitoes contain an 肥皂可中和蜜蜂螞蟻及蚊子螫過 acid. We can wash the affected area with an alkaline 的傷口上的酸性物質 substance, such as soap to neutralise the acid. mosquito 蚊子 The sting of a wasp is alkaline. We can apply an acidic substance, such as vinegar, on the affected area to neutralise the alkali. 醋可中和黃蜂螫過的傷口上的鹼性物質 wasp 黃蜂 4. Regulation of ph values of soil 4. 調節土壤的 ph 值 Many plants do not grow well in soil which is too 大多數植物都不適宜於過酸或過鹼 acidic or too alkaline. If the soil is too acidic, farmers 的土壤中生長假如土壤的酸性過 will add slaked lime (calcium hydroxide) to the soil 高, 農夫需要定期加入帶有鹼性的 before growing crops. On the other hand, if the soil is 熟石灰 ( 氫氧化鈣 ) 以中和土壤中 too alkaline, farmers may add sulphur to the soil. 的酸另一方面, 假如土壤的鹼性過高, 農夫會在土壤中加入硫 The farmer is adding slaked lime to neutralise acidic soil. 農夫在土壤加入熟石灰以中和土壤中的酸 18

19 30.3 Handling acids and alkalis 30.3 處理酸和鹼的方法 Q19 A19 What are the potential hazards of acids and alkalis? What safety precautions should we take when handling them? 使用酸和鹼時有甚麼潛在危險? 當我們使用這些溶液時應採取甚麼安全措? The following shows some potential hazards of acids and alkalis, and the corresponding safety precautions we should take when handling them. Potential hazard 1: Concentrated acids or concentrated alkalis can cause blindness if they get into the eyes. 潛在危險 1: 如果濃酸或濃鹼濺進眼睛, 可能會引致失明 Safety precaution 1: Wear safety goggles. 安全措施 1: 佩戴安全眼鏡下圖顯示使用酸和鹼時的潛在危險, 及我們使用這些溶液時應採取的安全措施 Potential hazard 2: The vapour of concentrated acids or concentrated alkalis is corrosive. 潛在危險 2: 濃酸或濃鹼的蒸氣具腐蝕性 Safety precaution 2: Carry out the experiment in a fume cupboard. 安全措施 2: 在煙櫥內進行實驗 PPotential hazard 3: Concentrated acids or concentrated alkalis can burn skin and flesh. 潛在危險 3: 濃酸或濃鹼會腐蝕皮膚和肌肉 Safety precaution 3: Wear protective gloves. 安全措施 3: 戴上保護性膠手套 19

20 Q20 How should we treat accidents and emergencies involving acids and alkalis? 一旦在實驗室使用酸或鹼時發生意外, 我們應如何處理? A20 When an accident involving acids or alkalis occurs, we must keep calm. We should report it to our teacher and take the following measures. 一旦在實驗室使用酸或鹼時發生意外, 必須保持冷靜, 立即向老師報告, 並依照下列的方法處理 : 1. Wash the affected area with slow running water for at least 10 minutes to avoid further damage to it. 1. 用清水慢慢沖洗沾有化學品的部位最少 10 分鐘, 以防止受傷組織遭到進一步破壞 2. If the eye is hurt, keep the affected eye open with one hand and rinse it with the eyewash bottle. 2. 若眼睛受傷, 應用手把受傷的眼睛撐開, 用洗眼瓶徹底沖洗 3. Gently remove any contaminated clothing. Care must be taken to avoid further contact with the acids or alkalis. 3. 小心地把沾有酸或鹼的衣物除下, 並應避免再次與酸或鹼接觸 4. If the accident is serious, keep washing the affected area until the ambulance crew arrives. A sample of the acids or alkalis should be taken to the hospital for reference. 4. 若傷勢嚴重, 則應不停沖洗受傷部位, 直至救護車到達應把傷者連同引致灼傷的酸或鹼樣本一併送往醫院 20

21 Q21 A21 What are the proper procedures in diluting concentrated acids and alkalis? 稀釋濃酸和濃鹼的正確步驟是怎樣的? The following shows the proper procedures in diluting concentrated acids and alkalis. 下圖顯示稀釋濃酸和濃鹼的正確步驟 CORRECT 正確 protective gloves 保護性膠手套 INCORRECT 不正確 no protective gloves 沒有戴上保護性膠手套 water 水 water 水 concentrated acid/alkali 濃酸或濃鹼 concentrated acid/alkali 濃酸或濃鹼 Carry out the process inside a fume cupboard. 應在煙櫥內進行 Add water to concentrated acid or alkali. 把水加入濃酸或濃鹼中 Wear protective gloves and safety goggles. 應戴上保護性膠手套及安全眼鏡 Carry out the procedures with bare hands. 沒有戴上保護性膠手套 Add concentrated acid or alkali slowly to a large amount of water. 把濃酸或濃鹼慢慢加入大量水中 Stir the solution continuously and slowly when you are adding concentrated acid or alkali. 把濃酸或濃鹼加入水時, 要小心地不斷攪拌溶液 Do not breathe in fumes from the cupboard. 避免吸入煙櫥內的煙霧 21

22 Part 2 第 Revision Helper 溫習錦囊 (Bilingual version) 雙語版本部分 Revision exercise 單元練習 A. True or false questions 是非題 Write T for a true statement or F for a false statement in each box provided. 細閱以下句子, 正確的在方格內填上 T, 不正確的則填上 F 1. Lemons contain citric acid. 2. Alkalis have a slippery feel. 3. Alkaline solutions turn blue litmus paper red. 4. Litmus can be used to indicate the degree of acidity or alkalinity of a substance. 5. The ph value of glass cleaner is less than Some metals react with acids to produce hydrogen. 7. The ph value of acid rain is lower than When an acid is added to an alkali, the ph value of the resulting solution increases. B. Multiple-choice questions 多項選擇題 Choose the correct answer for each of the following questions. 選出正確的答案, 然後在空格內填上代表該答案的英文字母 1. Which of the following statements about acids are correct? (I) All acids are not safe to consume. (II) Some drugs contain acid. (III) Vinegar contains ethanoic acid. A. (I) and (II) only B. (I) and (III) only C. (II) and (III) only D. (I), (II) and (III) 2. Which of the following substances are corrosive? (I) Nitric acid (II) Calcium hydroxide (III) Ammonia solution A. (I) and (II) only B. (I) and (III) only C. (II) and (III) only D. (I), (II) and (III) 3. Which of the following substances has a ph value greater than 7? A. Tap water B. Apple juice C. Drain cleaner D. Hair conditioner 22

23 4. Which of the following substances does not react with an acid? A. Limestone B. Copper C. Eggshell D. Zinc 5. Which of the following gases will be given out when an acid reacts with magnesium? A. Oxygen B. Nitrogen C. Hydrogen D. Carbon dioxide 6. Which of the following are the effects of acid rain on the environment? (I) It damages statues made of marble. (II) It kills organisms living in water. (III) It damages plants. A. (I) and (II) only B. (I) and (III) only C. (II) and (III) only D. (I), (II) and (III) 7. Which of the following gases may cause acid rain? (I) Nitrogen oxides (II) Nitrogen (III) Sulphur dioxide A. (I) and (II) only B. (I) and (III) only C. (II) and (III) only D. (I), (II) and (III) 8. Which of the following substances will be formed when an acid neutralises an alkali? (I) Water (II) Salt (III) Carbon dioxide A. (I) and (II) only B. (I) and (III) only C. (II) and (III) only D. (I), (II) and (III) 23

24 C. Short questions 短問題 1. The following table shows the ph values of five substances. Substance A B C D E ph value ~ 9 ~ 5 ~12 ~ 2 ~ 7 (a) Which substance(s) is/are acidic, neutral and alkaline? (b) Which substance is the most acidic? (c) Which substance is the most alkaline? (d) How does the ph value of the mixed solution change when substance A is added to substance D? 2. Alice carries out an experiment to study the reaction between dilute hydrochloric acid and aluminium. The following diagrams show the steps. aluminium inverted rubber stopper dilute hydrochloric acid aluminium (a) What do you observe after aluminium is added to the test tube? (b) She then puts a burning splint near the mouth of the test tube to test for the gas. What do you hear? burning splint (c) What gas is formed when aluminium reacts with dilute hydrochloric acid? 24

25 art Answers 答案 A. True or false questions 是非題 1. T 2. T 3. F 4. F 5. F 6. T 7. T 8. F B. Multiple-choice questions 多項選擇題 1. C 2. B 3. C 4. B 5. C 6. D 7. B 8. A C. Short questions 短問題 1. (a) Substances B and D are acidic. Substance E is neutral. Substances A and C are alkaline. (b) Substance D is the most acidic. (c) Substance C is the most alkaline. (d) The ph value of the solution increases. 2. (a) Some colourless gas bubbles are given out. (b) A pop sound (c) Hydrogen 25

UTI (Urinary Tract Infection) - Traditional Chinese

UTI (Urinary Tract Infection) Urinary tract infection, also called UTI, is an infection of the bladder or kidneys. Urethra Kidney Ureters Bladder Vagina Kidney Ureters Bladder Urethra Penis Causes UTI