MUSINGU HIGH SCHOOL
CHEMISTRY FORM ONE
APRIL 2014
HOLIDAY ASSIGNMENT
1.
2.
3.
4.
The diagram below shows a Bunsen burner when in use.
Name the region labelled C and D.
Samples of urine from three participants F, G and H at an international sports meeting were spotted onto a
chromatography paper alongside two from illegal drugs A1 and A2. A chromatogram was run using
methanol. The figure below shows the chromatogram.
a)
Identify the athelete who had used an illegal drug.
b)
Which drug is more soluble in methanol?
The graph below is a cooling curve of a substance from gaseous state to solid state.
Give the name of the:
a)
Process taking place between t0 and t1;
b)
Energy change that occurs between t3 and t4
For each of the following experiments give the observation, the type of change that occurs (physical or
chemical) and the formula (e) of any substance(s) formed. If no new compound (substance) is formed
write no new compound formed.
Experiment
Add few drops of concentrated
sulphuric acid to small amount of
sugar (C12H22O11)
A few crystals of Iodine I2 are heated
gently in a test tube.
Few crystals of Copper (II) Nitrate
are heated strongly in a test tube.
Sodium hydroxide platettes in an
evaporating dish are left in humid air
for one day.
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Observation
Type of change
Formulae
5.
7.
8.
9.
10.
11.
a)
b)
What method can be used to separate a mixture of ethanol and propanol?
i)Explain how a solid mixture of sulphure and sodium chloride can
be separated into solid sulphur and solid sodium chloride.
ii)How can one determine that solid sulphure is pure?
Name the methods by which the following substances could be separated.
a)
Kerosene from crude oil
b)
Coloured extract from grass dissolved in ethanol.
c)
Aluminium chloride from sodium chloride.
d)
Iron fillings from sulphur powder.
A laboratory technician accidentally mixed liquids suspected to be benzene (B.P. 78 0C). He has a
problem of separating the mixture and seeks your help. Describe to him.
a)
The method he should use
b)
The apparatus he should use
c)
The precautions he should take when carrying out the separation.
Study the following chart for laboratory preparation of dry nitrogen.
What would be observed when aqueous sodium hydroxide is added to aqueous Lead (II) Nitrate?
Solutions may be classified as strong basic, weakly acidic, strong acidic. The information below gives
solutions and their PH values. Study it and answer the questions that follow.
Solutions
PH values
B
1.5
C
6
D
14
Classify the solutions in the table above using the stated classification
a)
Give the name of each of the processes described below which takes place
when the salt are exposed to air for some time.
i)
Anhydrous Copper (II) Sulphate becomes blue.
ii)
Magnesium chloride forms an aqueous solution.
iii)
Fresh crystals of sodium carbonate (Na2CO3: 10H2O become
covered with a white powder of formula Na2CO3: H2O.
The table below shows the PH values of certain solutions
Solution
A
B
C
D
PH values
8
5
7
11
Which of the solutions is most likely to be solutions of
i)
Common salt
ii)
Lime water
iii)
Orange juice
iv)
Household soap
The diagram below represents two iron nails with some parts wrapped tightly with zinc and copper strips
respectively.
What observations would be made at the exposed points A and B if the wrapped nails are left in the open
for several months? Explain.
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