2. Demonstrate
understanding of
the term atom and
molecule.
State the
distinguishing
properties of
solids, liquids and
gases
Describe
qualitatively the
molecular structure
of solids, liquids
and gases.
Relate the
properties of
solids, liquids and
gases to the forces
and distances
between molecules
and to the motion of
the molecules.
4. Mass cannot be created or destroyed, it can
only be transformed into energy
In a Chemical Reaction the mass of the
products equals the mass of the reactants
http://sciencepark.etacude.com/chemistry/la
w.php
5. The smallest physical unit of an element or
compound. Consisting of one or more like
atoms in an element and two or more different
atoms in a compound.
8. Describe paper chromatography.
Interpret simple chromatograms.
Describe methods of separation and purification:
filtration, crystallisation, distillation, fractional
distillation.
Understand the importance of purity in substances
in everyday life, e.g. foodstuffs and drugs.
Identify substances and assess their purity from
melting point and boiling point information.
Suggest suitable purification techniques, given
information about the substances involved.
9. Chromatography is a technique for
separating mixtures into their components
in order to
analyze, identify, purify, and/or quantify
the mixture or components.
Separate
• Analyze
• Identify
• Purify
• Quantify
ComponentsMixture
10. Chromatography is used by scientists to:
• Analyze – examine a mixture, its components,
and their relations to one another
• Identify – determine the identity of a mixture or
components based on known components
• Purify – separate components in order to isolate
one of interest for further study
• Quantify – determine the amount of the a mixture
and/or the components present in the sample
11. Real-life examples of uses for
chromatography:
• Pharmaceutical Company – determine amount of
each chemical found in new product
• Hospital – detect blood or alcohol levels in a
patient’s blood stream
• Law Enforcement – to compare a sample found at
a crime scene to samples from suspects
• Environmental Agency – determine the level of
pollutants in the water supply
• Manufacturing Plant – to purify a chemical
needed to make a product
12. Detailed Definition:
Chromatography is a laboratory technique that
separates components within a mixture by using the
differential affinities of the components for a mobile
medium and for a stationary adsorbing medium through
which they pass.
Terminology:
• Differential – showing a difference, distinctive
• Affinity – natural attraction or force between things
• Mobile Medium – gas or liquid that carries the components
(mobile phase)
• Stationary Medium – the part of the apparatus that does
not move with the sample (stationary phase)
13. Simplified Definition:
Chromatography separates the components of a
mixture by their distinctive attraction to the mobile
phase and the stationary phase.
Explanation:
• Compound is placed on stationary phase
• Mobile phase passes through the stationary phase
• Mobile phase solubilizes the components
• Mobile phase carries the individual components a
certain distance through the stationary
phase, depending on their attraction to both of
the phases
14. Components
Affinity to Stationary
Phase
Affinity to Mobile
Phase
Blue ---------------- Insoluble in Mobile Phase
Black
Red
Yellow
Mixture Components
Separation
Stationary Phase
Mobile Phase
15.
16. • Liquid Chromatography – separates liquid samples with a
liquid solvent (mobile phase) and a column
composed of solid beads (stationary phase)
• Gas Chromatography – separates vaporized samples with a
carrier gas (mobile phase) and a column composed of a
liquid or of solid beads (stationary phase)
• Paper Chromatography – separates dried liquid samples
with a liquid solvent (mobile phase) and a paper strip
(stationary phase)
• Thin-Layer Chromatography – separates dried liquid samples
with a liquid solvent (mobile phase) and a glass plate
covered with a thin layer of alumina or silica gel
(stationary phase)
Types of Chromatography
17. (A) uses charge, (B) uses
pores, and (C) uses
covalent bonds to create
the differential affinities
among the mixture
components for the
stationary phase.
18. Capillary Action – the movement of liquid within the spaces
of a porous material due to the forces of adhesion, cohesion, and
surface tension. The liquid is able to move up the filter paper
because its attraction to itself is stronger than the force of
gravity.
Solubility – the degree to which a material (solute) dissolves
into a solvent. Solutes dissolve into solvents that have similar
properties. (Like dissolves like) This allows different solutes to
be separated by different combinations of solvents.
Separation of components depends on both their solubility in
the mobile phase and their differential affinity to the mobile
phase and the stationary phase.
20. Purpose:
To introduce students to the principles and
terminology of chromatography and
demonstrate separation of the dyes in Sharpie
Pens with paper chromatography.
Time Required:
Prep. time: 10 minutes
Experiment time: 45 minutes
Costs:
Less than $10
21. 6 beakers or jars
6 covers or lids
Distilled H2O
Isopropanol
Graduated cylinder
6 strips of filter paper
Different colors of
Sharpie pens
Pencil
Ruler
Scissors
Tape
22. • Prepare 15 ml of the following isopropanol solutions
in appropriately labeled beakers:
- 0%, 5%, 10%, 20%, 50%, and 100%
23. Cut 6 strips of filter
paper
Draw a line 1 cm above
the bottom edge of the
strip with the pencil
Label each strip with its
corresponding solution
Place a spot from each
pen on your starting line
24. Place the strips in the
beakers
Make sure the solution
does not come above your
start line
Keep the beakers covered
Let strips develop until
the ascending solution
front is about 2 cm from
the top of the strip
Remove the strips and let
them dry
29. 1. Dyes separated – purple and black
2. Not soluble in low concentrations
of isopropanol
3. Partially soluble in concentrations
of isopropanol >20%
Concentration of Isopropanol
0% 20% 50% 70% 100%
30. Concentration of Isopropanol
0% 20% 50% 70% 100%
1. Dye separated – blue
2. Not very soluble in low
concentrations of isopropanol
3. Completely soluble in high
concentrations of isopropanol
31. Concentration of Isopropanol
0% 20% 50% 70% 100%
1. Dye separated – blue and yellow
2. Blue – Soluble in concentrations
of isopropanol >20%
3. Yellow – Soluble in concentrations
of isopropanol >0%
32. 1. Dyes separated – red and yellow
2. Yellow –soluble in low concentrations of isopropanol and
less soluble in high concentrations of isopropanol
Concentration of Isopropanol
0% 20% 50% 70% 100%
3. Red – slightly
soluble in low
concentrations
of
isopropanol, an
d more soluble
in
concentrations
of isopropanol
>20%
33. Is a method of separation used to remove
undissolved solids from liquids.
Here, filter paper and a glass funnel is used to
separate the solid from the liquid.
The filter works by allowing the liquid to flow
through the paper, but not the solid.
This is because the particles of the solid are too big
to pass through the minute holes in the filter
paper.
At the end of the filtration, you are left the residue
of the solid on the filter paper and the liquid in
another container.
34. Is used to separate dissolved solids from
liquids, unlike filtration.
The solution is heated in an open container.
This allows the solvent to evaporate, leaving us
with a saturated solution.
The saturated solution is a solvent which contains
as much of the solid dissolved within it.
The saturated solution is left to cool.
At this point, crystals of the solid will grow in the
solution.
When the solution has completely evaporated, you
are left with the crystallized solids.
Distillation:
35. Is a method of separation used to extract a pure
liquid from a mixture.
How it works:
Credit: http://commons.wikimedia.org/w/in
dex.php?title=User:Ayapici&action=edit&redli
nk=1
36. In this example, we will use a mixture of both
ethanol and water.
The mixture is first heated in a round bottomed
flask.
The fact that ethanol has lower boiling point is
crucial.
At 78oc, the ethanol will evaporate into vapour.
At this point, the vapour will travel down the
condenser filled with cool, running water and be
cooled down into a liquid.
The ethanol liquid (distillate) will be collected into
a beaker whilst the water is left in the flask.
The ethanol is now separated from the water.
37. Is similar to the normal distillation method above.
Separates a liquid mixture into its individual components
How it works:
http://en.wikipedia.org/wiki/File:Crude_Oil_Distillation.png
The above diagram uses the example of crude oil.
Like distillation, the mixture is heated and evaporated.
The substances within the crude oil have different boiling points
and they each evaporate at different temperatures.
The temperature decreases as the gases go up the fractioning
column.
The smaller molecules condense at the higher portions of the
column at lower temperatures.
Conversely, the larger molecules sink to the bottom and
condense at higher temperatures
38.
39. Purifying and separation methods allow us to
obtain specific substances and chemicals needed
for our everyday life. Like above, the separation of
crude oil into its components is essential, as the
petrol allows us to keep our cars running and the
naphtha is used for making plastics.
Purifying chemicals and substances is
important, especially if we ingest it. Impurities in
things like drugs and food could be potentially
hazardous and detrimental to our health if
swallowed.
40. Identify physical and chemical changes, and
understand the differences between them.
41. Note: the physical and chemical properties of
the atoms will change when they combine to
another atom
42. 1 Describe the differences between
elements, compounds and mixtures.
Demonstrate understanding of the concepts of
element, compound and mixture.
44. 1 Describe the structure of an atom in terms of electrons and
a nucleus containing protons and neutrons.
3 State the relative charges and approximate relative masses
of protons, neutrons and electrons.
4 Define proton number and nucleon number.
5 Use proton number and the simple structure of atoms to
explain the basis of the Periodic Table (see C9), with special
reference to the elements of proton number 1 to 20.
6 Define isotopes.
2 Describe the build-up of electrons in ‘shells’ and
understand the significance of the noble gas electronic
structures and of valency electrons (the ideas of the
distribution of electrons in s and p orbitals and in d block
elements are not required).
48. Isotopes
The number of protons and electrons is the same
The number of neutrons changes for that atom or
element
49.
50. The electrons on the
outer most shell of
the atom.
S(2) P(6) D(10)
F(14)
Octet Rule- each
atom wants to have
at a full shell of 8
valence electrons.
51.
52. 1 Describe the formation of ions by electron
loss or gain.
2 Describe the formation of ionic bonds
between metals and non-metals as exemplified
by elements from Groups I and VII.
3 Explain the formation of ionic bonds between
metallic and non-metallic elements.
4 Describe the lattice structure of ionic
compounds as a regular arrangement of
alternating positive and negative
ions, exemplified by the sodium chloride
structure.
53. Atoms want a full outer shell, with 8 valence
electrons and will lose or steal electrons from
other atoms to fulfill this.
54. The number of
protons and
neutrons stays the
same
The number of
electrons changes
for that atom or
element
http://misterguch.bri
nkster.net/ionic.html
Cations: Metals lose
their electrons to
fulfill the octate
rule(and become
positive)
Anions: Non-Metals
steal electrons from
the Metals to fill up
their orbitals (and
become negative)
55.
56.
57.
58. 1 State that non-metallic elements form
nonionic compounds using a different type of
bonding called covalent bonding.
3 Describe the differences in volatility solubility
and electrical conductivity between ionic and
covalent compounds.
2 Draw dot-and-cross diagrams to represent the
sharing of electron pairs to form single covalent
bonds in simple molecules, exemplified by (but
not restricted to) H2, Cl2, H2O, CH4 and HCl.
4 Draw dot-and-cross diagrams to represent the
multiple bonding in N2, C2H4 and CO2.
59. The bonding between non-metals
The electrons are shared with
single, double, and triple bonds
60.
61. 1 Describe the giant covalent structures of
graphite and diamond.
2 Relate their structures to the use of graphite
as a lubricant and of diamond in cutting.
3 Describe the structure of silicon(IV) oxide
(silicon dioxide).
62. 1 Use the symbols of the elements to write the formulae of simple
compounds.
2 Deduce the formula of a simple compound from the relative
numbers of atoms present.
3 Deduce the formula of a simple compound from a model or a
diagrammatic representation.
4 Construct and use word equations.
5 Determine the formula of an ionic compound from the charges
on the ions present.
6 Construct and use symbolic equations with state
symbols, including ionic equations.
7 Deduce the balanced equation for a chemical reaction, given
relevant information.
8 Define relative atomic mass, Ar.
9 Define relative molecular mass, Mr, as the sum of the relative
atomic masses (relative formula mass or Mr will be used for ionic
compounds).
63. Symbol Meaning
+ Separates two or more reactants or products
→ Separates reactants from products
(s) Identifies solid state
(l) Identifies liquid state
(g) Identifies gaseous state
(aq) Identifies water solution
(aqueous)-mixture of water
64. Reactants →
Product(s)
C+O2 → CO2
CO2 + 2 H2→CH4+O2
In the law of
conservation of mass it
is stated that we can
neither lose or gain
mass so during a
chemical equation
what we put in
(reactants) has to equal
what is put out
(product)
For example: If you start
with 2 hydrogen atoms
and 1 oxygen atom as
your reactants then there
has to be 2 hydrogen
atoms and 1 oxygen
atom
http://misterguch.brinkst
er.net/eqnbalance.html
65.
66. Decomposition -when one
breaks down, or
decomposes, into two or
more substances
AB→A+B
2H2O(l)→2H2(g)+O2(g)
Single Displacement-
when one element
replaces another element
in a compound
A+BC→AC+B
Double Displacement-
when the positive ion of
one compound replaces
the positive ion of the
other to form two new
compounds
AB+CD→AD+CB
Ppt. (s)
Produce H2O
Get Gas as a product
Reversible
H2O↔OH+ +H+
Re-dox-you can reduce
oxidation number(gain
electron) or oxidized (lose
electron)
67. Factors that change the rates are
Concentration
When the concentration is increased of the reactants then
the rate increases too
Surface area
More surface are the faster the reaction is
Temperature
Endo-Cold
Exo-Hot
Catalysts-A substance that increases the rate of the
reaction and doesn’t change
68. 1 Define the mole in terms of a specific number
of particles called Avogadro’s constant.
(Questions requiring recall of Avogadro’s
constant will not be set.).
2 Use the molar gas volume, taken as 24 dm3 at
room temperature and pressure.
3 Calculate stoichiometric reacting masses and
reacting volumes of solutions; solution
concentrations will be expressed in mol / dm3.
(Calculations involving the idea of limiting
reactants may be set.)
69. 1 State that electrolysis is the chemical effect of electricity on ionic
compounds, causing them to break up into simpler substances, usually
elements.
2 Use the terms electrode, electrolyte, anode and cathode.
3 Describe electrolysis in terms of the ions present and the reactions at the
electrodes.
4 Describe the electrode products, using inert electrodes, in the
electrolysis of:
• molten lead(II) bromide,
• aqueous copper chloride,
• dilute sulfuric acid.
5 State and use the general principle that metals or hydrogen are formed
at the negative electrode (cathode), and that nonmetals (other than
hydrogen) are formed at the positive electrode (anode).
6 Relate the products of electrolysis to the electrolyte and electrodes
used, exemplified by the specific examples in the Core together with
aqueous copper(II) sulfate using carbon electrodes and using copper
electrodes (as used in the refining of copper).
70. 7 Describe the electroplating of metals, using
laboratory apparatus.
8 Predict the products of the electrolysis of a
specified binary compound in the molten
state, or in aqueous solution.
9 Describe, in outline, the chemistry of the
manufacture of
aluminium from pure aluminium oxide in molten
cryolite,
chlorine, hydrogen and sodium hydroxide from
concentrated aqueous sodium chloride.
71. http://en.wikipedia.org/wiki/Reactivity_series
On the reactivity series, hydrogen is less reactive
than sodium. Hence hydrogen will be produced
at the cathode (negative electrode.)
A metal will be produced if it is less reactive
than hydrogen
Hydrogen will be produced if the metal is more
reactive
The less reactive cation will be produced at the
cathode.
Reduction occurs at the cathode. Cations are
reduced (become neutral) by the e- at the
cathode.
72. When the hydrogen reaches the cathode, it is
reduced (gains electrons.) The e- flowing in the
circuit are attracted to the cation and the
hydrogen ions are neutralized (reduced to
neutral. 2H+ + e - → H2
74. Impure copper would be used as the anode and pure
copper would be used as the cathode in a copper
sulfate solution.
Electricity is applied and the copper atoms in the
anode are oxidized(their e- removed.)
Cu – 2e- → Cu2+
The copper ions dissolve into the copper sulfate solution
and are attracted to the copper cathode where they are
reduced (e- added) and pure copper is added to the
cathode.
Cu2+ + 2e- → Cu
As the rxn continues the cathode grows larger and
the anode shrinks.
75. Metal plating is similar to metal purification.
The object to be plated becomes the cathode.
The metal you are plating (coating) on the
object is the anode.
The electrolyte used in electroplating must
contain the same ions as the metal you are
plating onto the object.
When electricity flows the metal that is
being plated onto the object is first oxidized
and become ions in the solution. They are
attacted to the cathode and reduced.
Leaving a layer of metal on the object.
76. The electrolysis of aqueous solutions of sodium
chloride doesn't give the same products as
electrolysis of molten sodium chloride.
Electrolysis of molten NaCl decomposes this
compound into its elements.
2 NaCl(l)→2 Na(l) + Cl2(g)
77. Electrolysis of aqueous NaCl solutions gives a
mixture of hydrogen and chlorine gas and an
aqueous sodium hydroxide solution
2 NaCl(aq ) + 2 H2O(l) →2 Na+
(aq) + 2 OH-
(aq) + H2(g)
+ Cl2(g)
http://chemed.chem.purdue.edu/genchem/top
icreview/bp/ch20/faraday.php#aq
78. The Hall–Héroult process is the major
industrial process for the production of
aluminium. It involves dissolving alumina in
molten cryolite, and electrolysing the molten
salt bath to obtain pure aluminium metal.
79. The molten mixture of
cryolite, alumina, aluminum fluoride is
electrolyzed using DC. Aluminum is
deposited at the cathode
(precipitate), and oxygen with carbon
from the anode produces CO2. The rate of
reaction proportional to the amount of current. While
solid cryolite is denser than solid aluminum (at room
temperature), liquid aluminum is denser than the
molten cryolite and Al sinks to the bottom of
the electrolytic cell, where it is
periodically collected.
http://www.gcsescience.com/ex11.htm
80. A , chemical reactions where electrons are
transferred between molecules are called
oxidation/reduction (redox) reactions.
In contrast, chemical reactions driven by an
external applied voltage = electrolysis. In
general, electrolysis deals with situations
where oxidation and reduction reactions are
separated in space or time, and connected by
an external electric circuit.
81. The loss of electrons from an atom or molecule is
called oxidation.
The gain of electrons is reduction.
mnemonic devices.
"OIL RIG" (Oxidation Is Loss, Reduction Is Gain)
"LEO" the lion says "GER" (Lose Electrons:
Oxidization, Gain Electrons: Reduction).
