Unit 4 sources of
chemicals
• Aims and Requirements
1. Mastering New words and terminology;
2. Comprehending the text and related
background knowledge accurately;
3. Mastering typical expressions in the text.
• Important and Difficult Teaching Points
1. Explanation of the specialized words and
terminology;
2. Analyzing the structure of the complex
sentence;
3. Comprehending and translating the text.
一、New words and expressions
• 3.covalent a. 共价的
•
covalent bond n.[化]共价键
• 4.bond
• 5.isomerism
•
cis-trans isomerism顺反异构
•
stereo isomerism立体异构(现象)
7.detergent 洗净剂; 去污剂
• surfactant表面活化剂; 能减低表面张力
的物质或溶液(如清洁剂)
32.particulate n.微粒 adj.微粒的
• suspended particulate悬浮颗粒; 悬浮
性粒子
• 34.surface-active agent =surfactant
• 38.via=By way of:经过：
•
went to Pittsburgh via
Philadelphia.经过费城到匹兹堡
• 68.decline v. To express polite
refusal.
• To slope downward; descend.
• They wish that prices would decline.
他们希望物价能下降。
二、 Text Explanation
• Qustions:
• 1.Compare the sources of inorganic
chemicals with that of organic
chemicals.
• 2.Give an example of the extraction
process for processing inorganic
chemicals.
• 3.Distinguish between non-renewable
resource and renewable resource.
And show the relative values of oil in
the different forms.
• 4.Evaluate the advantages and
disadvantages of the fermentation
process.
Question:
Compare the sources of
inorganic chemicals with that
of
organic chemicals.
Words:
compare to
compare with
Sentences
• 1.Even this vast number pales into
insignificance [when compared to the
number of carbon compounds which is
theoretically possible].
• pales into insignificance 变得微不足
道
• 2. However, [of the remainder] there
are probably several thousands which
are of commercial and practical
interest.
• are of commercial and practical
interest 具有商业和实际应用价值.
• Be of n. = be adj.
• 3. It might therefore be expected that
there would be a large number of sources
of these chemicals. Although this is true
for inorganic chemicals, surprisingly most
organic chemicals can originate from a
single source such as crude oil( petroleum ).
• This=there would be a large number of
sources of these chemicals
1. Inorganic Chemicals
Question:
Give an example of the extraction process
for processing inorganic chemicals.
Words:
on one’s own 独自；自己单独地；
凭自己力量
in question 上述的
Sentences
• 4. If therefore the individual element or
elements, say the metal, are required then
the extraction process must involve
chemical treatment in addition to any
separation methods of a purely physical
nature.
• in addition to ,除...外还有……
2. Organic Chemicals
Questions:
1. Distinguish between non-renewable resource and
renewable resource.
2. Show the relative values of oil in the different
forms.
3. Evaluate the advantages and disadvantages of the
fermentation process.
Words:
1011 读作ten to the power of eleven, or the
eleventh power of ten, or ten to the eleventh power。
compete with M for N 与M争取N
barrel
桶
A Barrel (bbl.) of crude
contains 42 gallons or 158.8 liters. No one actually ships
petroleum in barrels anymore because they are too small,
but the term is still used to describe a defined volume.
Sentences
• 5. This is a very interesting situation —one which
has changed over the years and will change again
in the future—because technically these same
chemicals could be obtained from other raw
materials or sources.
• —one which has changed over the years and will
change again in the future—同位语
• 同位语的符号—……….—; (………….); ,……………..,
i.e………..
• 6. The formation of fossil fuels, i.e. oil gas
and coal reserves, takes millions of years
and once used they cannot be replace. they
are therefore referred to as non—
renewable resources.
• renewable resources 可再生资源
• i.e.=that is
• 7. Clearly alternative energy sources
to fossil fuels are now available if we
have the will to use them, and we can
confidently expect other alternatives
to become available in the not too
distant future.
• 这里will 是决心，意志的意思
• 8. It is interesting, and salutary, [to note
that as early as 1894 Mendeleyev ( the
Russian chemist who developed the
Periodic Table ) reported to his
government that “oil was too valuable a
resource to be burned and should be
preserved as a source of chemicals.”]
• It形式主语
• 9. Some of these processes have been
used in the domestic situation for many
thousands of years, the best-known
example being fermentation of grains to
produce alcoholic beverages.
• the best-known example being 最为熟知的
例子是
• 10. Indeed up until about 1950 this was
the most popular route to aliphatic organic
chemicals, since the ethanol produce could
be dehydrated to give ethylene, which is
the key intermediate for the synthesis of
a whole range of aliphatic compounds.
•
• key intermediate关键中间体
• 11. Major disadvantages of fermentation
[compared with petrochemical
processes ]are , firstly, the time scale,
which is usually of the order of days
compared to literally seconds for some
catalytic petrochemical reactions, and
secondly, the fact that the product is
usually obtained as a dilute aqueous
solution (< 10% concentration ).
• 12. On the other hand particular
advantages of fermentation methods
are (that they are very selective and
that some chemicals which are
structurally very complex, and
therefore extremely difficult to
synthesize, and/or require a multistage synthesis, are easily made.)
• 13. Provided that the immense practical
problems associated with the rapidly
developing field of genetic engineering,
[where micro-organisms such as bacteria
are ‘tailor-made’ to produce the required
chemical], can be overcome, then the
interest in fermentation methods will be
very considerable.
• Provided that =if 如果,只要,倘若
The advantages and disadvantages
of the fermentation process:
Advantages
1.
2.
high selectivity
structurally
complex chemical
3.
4.
renewable resources
Disadvantages
higher raw material costs
very high separation and
purification costs
difficult and expensive
transportation
long time scale
三、Exercises
• P42
Exercise 1
Exercise 2
科技术语构成（1）
一、合成法
1. 名词＋名词
octane number
limitation reaction
2. 形容词＋名词
biological degradation
molecular formula
3. 动名词＋名词
alkylating reaction
antibonding orbital
4. 过去分词＋名词 saturated hydrocarbon
branched chain
5. 名词＋动名词
6. 名词＋过去分词
7. 名词＋形容词
oxygen-containing
hand-made
snow-white
paper-thin
8. 形容词＋形容词
red-hot
dark-blue
light-yellow