S.5Chemistry04 Final Exam reviews - PowerPoint PPT Presentation

Title: S.5Chemistry04 Final Exam reviews


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S.5 Chemistry 04 Final Exam reviews

• Q.4 Not many students can tell the contact
  process steps by steps.
• Getting SO2 from burning of sulphur.
• .Purify the SO2(as catalyst can be poison
  easily.)
• SO2(g) O2(g) ? SO3(g)
• SO3 H2SO4 ? H2S2O7
• H2S2O7 H2O ? 2H2SO4

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S.5 Chemistry 04 Final Exam reviews
Q.5 Most students say no petroleum means no
energy. But we will have solar energy, tidal
power, wind power etc.
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S.5 Chemistry 04 Final Exam reviews
Q6a) (i) Student should realize that heating
metal in air will cause corrosion. (ii) Fill the
bulb with noble gas is acceptable. But they
should choose the noble gas Argon which is 3rd
most abundance gas in atmosphere (N2 78 ,
O2 21 , Ar 1 , CO2 0.03 ).
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S.5 Chemistry 04 Final Exam reviews
Q.7a) (ii) (2)Some students still get confusion
between mobile electrons and mobile
ions. Some of them didnt realize the bonding
in metal are metallic bonds but not ionic
bonds. Q.7 b) In general, many students didnt
use the mole ratio between H2O and Na2CO3 to
determine the value of x in Na2CO3 x H2O.
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S.5 Chemistry 04 Final Exam reviews
Q.8a)(i)(4) Students should know that Y is a
graphite and oxygen will be formed at Y. In
this way, they are able to deduce the change
C O2 ? CO2. Q.8a)(ii) Students cant make
a connection between extraction of aluminium
needs an electrolysis and the use of
electricity is only begun at a 100 years ago.
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S.5 Chemistry 04 Final Exam reviews
Q.9. (v) Writing equation for polymerization is
still a weakness in most students.
C C double bond
Each C must be 4 bonded.