F2 IS 2nd Term WS05 10.1 Answers

10.1    Acids and alkalis in daily life

i      Words to know:

	English term	Write the words again	Chinese term
1	Acid		酸
2	Sour		酸味的
3	Lactic acid		乳酸
4	Citric acid		檸檬酸
5	Ethanoic acid		乙酸
6	Hydrochloric acid		氫氯酸
7	Carbonic acid		碳酸
8	Alkali		鹼
9	Bitter		苦味
10	Soapy		似肥皂的
11	Slippery		滑溜的
12	Ammonia		氨
13	Sodium hydroxide		氫氧化鈉
14	Potassium hydroxide		氫氧化鉀

i      Fill in the blanks:

1      In our daily life, there are many foods, drinks and flavourings that taste sour. It is because they contain

         acid. For example,

n   Yoghurt contains lactic acid.

n   Lemons contain citric acid.

n   Vinegar contains ethanoic acid.

2      Many household cleaners and personal care products also contain acids. For example,

n   Toilet bowl cleaners contain hydrochloric acid.

3       Alkalis are the chemical opposite of acids. They generally taste bitter, and feel soapy and slippery.

4       Besides soap, some household cleaners contain alkalis. For example,

n   Glass cleaners contain ammonia.

n   Drain and oven cleaners contain sodium hydroxide or potassium hydroxide.

i      Everyday Science:

1.       Fizzy soft drinks contain carbonic acid which is formed by dissolving carbon dioxide in water.

2.       The gastric juice (胃液) in our stomach (胃) contains hydrochloric acid.