Deans Community High School
Chemistry Department
National 5
Homework Booklet
Homework 1– Chemical Reactions
1.
Write down three examples of everyday chemical reactions.
2.
Write word equations for the following reactions:
(a) Hydrogen joins up with oxygen to form water.
(b) The reaction of sulphuric acid with calcium carbonate produces
calcium sulphate, carbon dioxide and water.
(c) Silver oxide breaks up when heated to form its elements.
(d) Ammonium sulphate is produced by the reactions of ammonia with
sulphuric acid.
3. If a substance effervesces (fizzes), is there a chemical reaction taking
place?
Explain your answer.
4. The first 20 elements (hydrogen to calcium) in the periodic table were all
discovered before the twentieth century began. Use the data booklet (page
8) to help you answer the following questions about these elements.
(a) Which two elements were known in prehistoric times?
(b) Which elements were discovered in the 18th century?
(c) Name three elements from your periodic table which are named after
famous scientists.
5. Name two elements which are:
a
b
c
d
e
f
g
metallic
non-metallic
solid at room temperature
liquid at room temperature
gas at room temperature
naturally occurring
made by scientists
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6. The elements are arranged in the Periodic Table
a
What is meant by a group?
b
What is meant by a period?
c
Give an example of a physical similarity of elements
in group 1.
d
Give an example of a chemical similarity of elements
in group 1.
7. Divide the following list of substances into elements and compounds.
carbon, petrol, alcohol, zinc, oxygen, sugar, sodium chloride, gold,
copper sulphate, nitrogen, aluminium, silver oxide
8. Explain what is meant by
(a)
an element
(b)
a compound
(c)
a mixture
(d)
a solute
(e)
a solvent
(f)
a solution
9. Name the compound which is formed when each of the following pairs of
elements join up.
(i) magnesium and chlorine
(ii) lead and sulphur
(iii) sodium and oxygen
(iv) hydrogen and iodine
10.
Name two possible compounds containing potassium, sulphur and oxygen.
11.
(a)
(b)
12.
What elements are present in:
(a)
(b)
13.
How many elements are there in compounds whose names end
in “ide”.
If a compounds name ends in “ite” or “ate”, what does this tell you
about the number of elements in the compound and which element
is always present?
sulphur oxide
potassium sulphate
(c)
(d)
phosphorus chloride
lithium sulphite
Crude oil is a mixture of compounds.
Explain clearly what is meant by this statement
2
Homework 2 – Speed of Reactions
1.
List the following in order of rate of reaction, fastest first:
Milk turning sour
A motor car rusting
Frying an egg
Striking a match
2.
The grid shows factors that can affect the speed of a chemical reaction.
A
B
increase in
particle size
D
C
increase in
concentration
E
decrease in
particle size
increase in
temperature
F
decrease in
concentration
decrease in
temperature
Identify the factor responsible for the change in speed of reaction in
each of the following examples.
(a) Seawater corrodes iron jetties near the Equator more quickly than in
northern Scandinavia.
(b) Magnesium ribbon burns more slowly than magnesium powder.
(c) Two scoops of biological detergent in a washing machine remove stains
from clothing more quickly than using one scoop.
3.
The speed of a reaction depends on the reaction conditions. Describe
how each of the following affects the speed of a reaction.
a)
particle size of the reactants
b)
concentration of reactants
c)
temperature of reactants
d)
using a catalyst
4.
Explain each of the following
a)
A log burns faster if it is chopped into small sticks
b)
Food is preserved longer when stored in a fridge
c)
Plants grow faster in a greenhouse than in the open air
5.
Three experiments were set up as shown. Each experiment is carried out
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at room temperature and the mass of magnesium is the same in each case.
(a)
Explain any difference that would be observed between
(i)
A and B
(ii)
A and C
(b)
Explain any difference that would be observed if experiment A
was repeated at 50oC
Homework 3 – Speed of Reactions
Interpreting Graphs
1. The graph shows the volume of carbon dioxide produced in the reaction
of
(i)
calcium carbonate powder
(ii)
calcium carbonate lumps
with excess dilute hydrochloric acid
Volume
of carbon
dioxide /
cm3
x
y
Time / s
a)
b)
2.
Which graph, X or Y, shows the results of using calcium carbonate
powder?
State three variables that must be kept the same when comparing
the reactions
5g of magnesium ribbon was added to excess sulphuric acid and the
Volume
of
hydrogen
/ cm3
4
Time / s
a)
b)
volume of hydrogen gas evolved was measured. A graph of the result is
shown below:Copy the graph and draw a line to show how the volume of hydrogen
produced would compare if 5g of magnesium powder was added to the
acid.
Draw another line of the graph showing the volume of hydrogen produced
if 2.5g of magnesium ribbon was added.
Homework 4 – Atomic Structure
1.
a
b
c
d
e
2.
3.
What name is given to the "core" at the centre of an atom?
What charge has this part of the atom?
What name is given to the particles which move around
outside the centre of the atom?
What charge do these particles have?
Explain why an atom is neutral.
Name the elements with each of the following atomic numbers:
(i)
23
(ii)
3
(iv)
28
(v)
17
(iii)
18
a
Name the elements with each of the following electron
arrangements:
(i)
(iii)
b
2, 8, 1
2, 4
(ii)
(iv)
2, 8
2, 8, 4
Which two elements will have similar chemical properties?
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4.
Copy and complete the following table:
Particle
Proton
Neutron
Electron
5.
Ne
N
Ca
A
B
C
6.
Charge
Location
Copy and complete the following table:
Element
(b)
Mass
Atomic
Number
Mass
Number
Number
of Protons
Number
of
Neutrons
Number
of
Electrons
22
7
40
4
9
14
89
Identify elements A, B, and C
6
36
Calculate the number of protons neutrons and electrons in each of the
following atoms of elements.
(i)
23
Na
11
(iv)
16
(ii)
35
Cl
17
(iii)
39
K
19
O
3
7. Calculate the number of protons, neutrons and electrons in each of the
following ions of elements
(i)
23
Na+
11
(iv)
(ii)
35
-
Cl
17
(iii) 40
20
32
S216
6
Ca2+
20
8.
9.
Ne and
22
Ne are two different kinds of neon atom.
(a)
In what way are the neon atoms different?
(b)
Explain why these atoms can be regarded as atoms of the same
element.
Copper has a relative atomic mass of 63∙5. It contains two isotopes.
63
65
Cu
Cu
(a)
How many neutrons are present in each of the two atoms?
(b)
Which of the two atoms is more common in copper?
Homework 5 – Covalent Bonding
1.
(a)
Explain what is meant by
(i)
(ii)
H
a molecule
a chemical formula
(b)
Write the chemical formula for each of the following
substances:
=H
(i)
(ii)
H
O
C
H
H
H
2.
3.
H
H
H
H
Molecules are made up of non-metal elements held together by covalent
bonds. Which of the following compounds will be made up of molecules?
(a)
(c)
(e)
(a)
sodium chloride
(b)
CH3Cl
hydrogen chloride
(d)
MgO
aluminium nitrate
(f)
NO2
Explain what is meant by a diatomic molecule
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(b)
Which of the following elements exist as diatomic
molecules?
Calcium
Carbon
Nitrogen
Aluminium
Hydrogen
Neon
Chlorine
Sulphur
Magnesium
Oxygen
Fluorine
Argon
(c)
Which diatomic element has a triple covalent bond between
the atoms?
4.
5.
Write the formula for each of the following substances.
(i)
sulphur trioxide
(ii)
phosphorus
pentachloride
(iii)
carbon monoxide
(iv)
silicon tetrachloride
(v)
hydrogen oxide
(vi)
phosphorus fluoride
Draw target diagrams to show how the outer electrons are arranged in
each of the following elements:
(i)
hydrogen
(iii)
oxygen
(ii)
(iv)
8
phosphorus
fluorine
6.
7.
Draw lewis diagrams to show how the outer electrons form covalent bonds
in each of the following molecules:
(a)
hydrogen
(b)
oxygen
(c)
nitrogen
(d)
hydrogen oxide
(e)
phosphorus chloride
(f)
carbon fluoride
Explain fully what a covalent bond is.
Homework 6 – Ionic Bonding
1.
Why are the noble gases unreactive?
2.
How do metal atoms achieve electron arrangements similar to that of
noble gases?
3.
How do non-metal atoms achieve electron arrangements similar to
that of noble gases?
4. (a) Copy and complete the following table to show the numbers of
protons and electrons in each of the following ions.
Ion
Number of
Protons
Number of Electrons
2+
Ca
ClAl3+
O2Na+
9
(b)
For each of the ions in the table above write their electron
arrangement and identify the noble gas with the same
arrangement.
5. (a) Explain clearly what happens when
(i)
an atom of fluorine forms a fluoride ion.
(ii)
an atom of lithium forms a lithium ion.
(b)
What happens during the formation of an ionic bond in lithium
fluoride?
6.
A compound is formed from a Group 2 element and a Group 6 element.
Choose two elements and show by means of a diagram what happens to
the electrons in the outer shell of the atoms involved.
7.
What is meant by an ionic lattice?
Homework 7 Properties of Substances
1.
(a)
By means of a labelled diagram, show the experimental apparatus
which can be used to classify substances into conductors and nonconductors.
(b)
Study the following list of solids.
nickel, iodine, copper, magnesium, sulphur, sodium, phosphorus,
scandium
Arrange the solids into two columns, headed conductors and nonconductors.
(c) Study the following list of liquids:
petrol, copper sulphate solution, silicon tetrachloride,
hexene, liquid oxygen, molten sulphur, sodium chloride
solution, mercury, strontium nitrate solution, molten iron
Arrange the liquids in two columns, headed conductors and nonconductors.
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2.
Study the following list of substances:
glucose, sulphur, sodium bromide, paraffin wax, silicon dioxide,
silver, potassium, carbon tetrachloride, potassium, nickel chloride
(a)
Name the substances which conduct electricity when solid.
(b)
(i)
Name the substances which conduct electricity when
in aqueous solution.
(ii)
Explain why the solutions you have chosen do not
conduct when solid.
3. The table below shows some properties of two chlorides.
Chloride
M.pt. / oC
B.pt. / oC
XCl
YCl4
801
1417
Solubility in
water
soluble
-23
77
insoluble
(i)
Which of these chlorides would you expect to be covalent and
which is likely to be ionic?
(ii)
In which group of the Periodic Table would you expect to
find element X?
4.
A pupil carried out experiments to investigate what happens during
electrolysis of melts. Explain what is meant by electrolysis.
5.
Shown below is a list of compounds and their colours.
sodium chloride
sodium selenate
nickel sulphate
white
white
green
State the colour of
(a) copper selenate
(c) nickel chloride
sodium sulphate
copper sulphate
vanadium sulphate
white
blue
violet
(b) vanadium chloride
11
the
6.
A crystal of copper dichromate was placed on moist filter paper at position X. When a high voltage was applied, a blue colour moved towards the
negative electrode while an orange colour moved towards the positive
electrode.
250 V
d.c.
X
(a)
(i)
What can be learned from this experiment about the
colour and charge of the dichromate ion?
(ii)
Explain your answer.
(b)
State any safety precaution which should be observed in this
experiment.
7. A pupil carried out an experiment to investigate the products of the
electrolysis of nickel bromide solution.
(a)
Explain why a d.c supply is used for this experiment.
(b)
Explain what would be seen at the negative electrode.
(c)
Explain what would be seen at the positive electrode.
(d)
Write ion-electron equations for the change at each
electrode.
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8.
Water in swimming pools can be purified using a chlorinating cell. Sodium
chloride solution is electrolysed in the cell to produce chlorine.
sodium chloride
powder
water from
pool
9.
chlorinated
water to pool
pump
chlorinating cell
(a)
Why can solid sodium chloride not be electrolysed?
(b)
(i)
(ii)
At which electrode is chlorine produced?
Describe what is happening in the formation of
chlorine.
The following table shows the properties of four substances.
Property
appearance
solubility in water
electrical conductivity
melting point /
o
C
boiling point /
oC
P
sparkling solid
Q
silvery liquid
R
insoluble
insoluble
soluble
soluble
does not
conduct
conducts
when solid
or molten
conducts
when molten or in
solution
does not
conduct
3547
-61
801
-115
4827
357
1417
59
white solid
S
colourless
liquid
For each of P, Q, R and S, explain whether the substance is likely to be a metal,
an ionic compound or a covalent compound (small molecule or network).
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Homework 8 – Writing Formulae
1.
Write formula for each of the following compounds.
(a)
(c)
(e)
(g)
2.
5.
hydrogen oxide
carbon hydride
aluminium chloride
barium bromide
carbon monoxide
sulphur dioxide
phosphorous pentachloride
(b)
(d)
(f)
silicon dioxide
sulphur trioxide
dinitrogen tetroxide
Write formula for each of the following compounds.
(a)
(c)
(e)
(g)
4.
(b)
(d)
(f)
(h)
Write formulae for each of these compounds with meaningful names.
(a)
(c)
(e)
3.
silicon bromide
phosphorous iodide
magnesium chloride
calcium sulphide
sodium bromide
potassium sulphide
iron (III) oxide
nickel (I) sulphide
(b)
(d)
(f)
(h)
calcium chloride
aluminium oxide
cobalt (II) chloride
titanium (III) nitride
Write formula for each of the following compounds containing a group ion.
(a)
lithium nitrate
(f)
sodium hydrogencarbonate
(b)
calcium carbonate
(g)
potassium
(c)
calcium chromate
(h)
magnesium
(d)
barium sulphate
(e)
aluminium hydroxide
hydrogensulphite
hydrogencarbonate
Write formula for each of the following compounds containing both a
transition metal and a group ion.
(a)
lead (II) carbonate
(b)
iron (III) sulphate
(c)
silver (I) chromate (d)
iron (III) hydroxide
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15
Name: ________________________
Teacher: ___________________
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