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www.fungsir.net Preparation p.1 Chemical preparation method
1. To prepare better fuels, which burnt with less air pollutants ------ Cracking (. )
Cracking breaks down large hydrocarbon molecules into many small hydrocarbon molecules
in the presence of heat and catalyst but no air. (e 0` pÅ á
Catalyst. porous pot / stone
gaseous alkane and alkene
or aluminum oxide
with heavy oil Heat ª -j ˜
HHHHH HHHHH HHHHH CCCCCH HCCCCC HHHHH HHHHH 2. To prepare ethanol by fermentation s²½(è
HCC HHH ) Procedure. Put some cooked rice and yeast solution
in a conical flask. Then stopper it.
After a few days, ethanol is obtained.
glucose 2 CO2 + 2 CH3CH2OH H cooked rice and yeast solution .
3. Preparation p.2 To prepare polystyrene from styrene (
Procedure. Pour some liquid styrene and kerosene (catalyst) into the experimental set-up of
heating under reflux (.
). HH H CC C C H C6H5 n H
H C6H5 n opening .
water out .
¬Ø condenser .
reaction mixture¬ Ø
boiling stones Ø
:ª ½, ¬ and heat . 4. To prepare urea-methanal thermosetting plastic ,(ø
:ª ½ ¬
Dissolve white urea solid in colorless methanal liquid in a test tube, then adding
few drops of concentrated sulphuric acid as catalyst.
Observation. At this moment, heat and colorless vapour (water vapour) are evolved and white
solid (urea-methanal) is formed. .
www.fungsir.net Preparation p.3 5. To prepare chlorine bleach by electrolysis of brine (
In the electrolysis of concentrated sodium chloride solution, chlorine gas is
formed at positive electrode (anode) and hydrogen gas is formed at negative
electrode (cathode). Afterwards, sodium hydroxide is left in the solution.
Finally, reacting chlorine and NaOH solution can produce chlorine bleach.
2 NaOH + Cl2
NaOCl + NaCl + H2O 6. To prepare ester by esterification (. ) Procedure. Adding alkanol and alkanoic acid and few drops of concentrated sulphuric acid
(catalyst) into the set-up of heating under reflux. Stop heating when there is a
fruity smell. Then pour the product mixture into concentrated NaCl solution to
salt out the ester. Finally, use filtration to get the solid ester.
filter funnel and
ester solid is formed
on solution surface
solid ester conc. NaCl solution Example. ethanol + butanoic acid water + ethyl butanoate (. O O
CH3 CH2 O H + HO C CH2CH2CH3 ) H2O + CH3CH2 O C CH2CH2CH3 .
7. Preparation p.4 To prepare soap by saponification (
Heat oil and sodium hydroxide solution until two layers of liquid become one.
Then cool down it. Afterwards, pour the product mixture into concentrated
NaCl solution. Finally, get the solid soap by filtration.
oil or grease
soap cool down
+ NaOH soap Two layer of liquid
become one layer.
for 30 mins
Pour the product mixture
into conc. NaCl solution O O
C17H33 8. C O C3H7 + NaOH C17H33 C O Filtration +
Na + C3H7 OH To prepare nitrogenous fertilizer ---------- large ammonia sulphate crystal
Procedure. Adding same molarity of ammonia solution and sulphuric acid in volume ratio
of 2. 1. Then heat the solution until it becomes saturated (. ).
Let it cool down and place it in room for few days. Large crystal is then formed. Obtain it
by filtration (. ).
2 NH3 + H2SO4
(NH4)2SO4 cool down Large
crystal XXXXXXXX Saturated
Heat Large crystal ...
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This note was uploaded on 09/02/2011 for the course CHINESE 12 taught by Professor Cn during the Spring '11 term at CNUAS.
- Spring '11