Level 3 Chemistry
STUDENT INFORMATION FOR AN EXTENDED
CHEMISTRY PRACTICAL INVESTIGATION: Achievement Standard 91387 V1
“Carry out an investigation in chemistry involving quantitative analysis”
4 credits
Achievement
Carry out an investigation in
chemistry involving quantitative
analysis.
Achievement with Merit
Achievement with Excellence
Carry out an in-depth investigation
in chemistry involving quantitative
analysis.
Carry out a comprehensive
investigation in chemistry involving
quantitative analysis.
Investigation Process
1. Choose your topic:
 In your group, define the purpose of your investigation, conduct background
research, and identify how you will ensure safety. The purpose should include
exploring a possible trend or pattern.
 You may plan and carry out the investigation in groups, but each student must collect
data for at least one independent variable. (This is shared with the group).
 Students keep a logbook, process the group data, and write their report individually.
 You will be provided with a range of topics that are suitable for investigation.
 Instructions for an appropriate analytical technique that can be used in a school
laboratory will also be provided.
 Data must be quantitative and collected by an analytical technique – acid/base,
oxidation-reduction or precipitation titrations, gravimetric or colorimetric analysis.
 You will be carrying out the investigation in your group and about 8 hours of class
time will be allocated to carry out the practical work required for this assessment. The
majority of the practical work will be carried out on the practical day – September 9th
or 10th (depending on class)
 The analysis of the data and the writing of your report will be done individually (using
the results gathered by your group), and will be completed outside of class time.
2. Define your purpose
 Your purpose (aim) is to investigate, by quantitative analysis, a possible trend or
pattern in the amount or concentration of a substance. The amount or
concentration (dependant variable) can be expressed in moles, grams, moles per
litre, grams per litre or as a percentage.
 A typical trend can be investigated with respect to method of treatment of a product
(the independent variable) e.g. temperature, time of exposure, storage conditions.
 A typical pattern can be investigated with respect to material gathered from different
sources e.g. soil from different places, different varieties of cheese
3. Do some background research and check safety
 Research your topic, e.g. search the internet, read reference books, consult an
expert. Background information could include reports on scientific work related to
your topic, your experimental procedure and/or information about the substances
involved. Record details of the references and people you consult so that you can
acknowledge them in your final report.
Practical Invest 2014
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Determine all the chemicals required. Identify substances that are:
Flammable, harmful, irritant, oxidising, explosive, toxic or corrosive
and state how you will use them safely.
Identify other safety considerations e.g. use of a fume hood, no naked flames, control
of temperature if energy is released when two chemicals are mixed.
You must each keep a logbook that records your progress, all raw data and
calculations. The logbook will be in the form of a Google.doc (using Google
Chrome). Data collected on the practical day, will be recorded by hand on refill or in
the Google.doc. All research (google.doc + raw data) must be submitted with the
final report.
Your individual report will be written up in a separate Google.doc to allow feedback
from your teacher. This must be printed for handing in and the ownership changed to
your teacher, and your editing rights removed.
4. Plan your practical work and do some trials
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You should carry out preliminary trials to establish suitable concentrations and
quantities and to identify variables that need to be controlled. These trials may be
‘small scale’. Records of any preliminary work must be recorded in your logbook
which will be submitted with your final report.
For chemicals required, determine approximate quantities and concentrations
needed. You will be required to make up your own standard solutions and
standardise them.
Your plan must detail procedures that will make sure you obtain sufficient,
appropriate and consistent data to enable you to write a valid conclusion that is
linked to the purpose of your investigation. The steps you specify in your plan must
be justified in relation to the reaction(s) occurring and to the nature of the samples
used. Titre volumes should be at least 5 mL to reduce the percentage error due to
equipment used.
When carrying out a titration it is important to get concordant data for each sample to
ensure reliability of the titration procedure.
5. Collect and record data (Group)
 Each member of the group should collect and record data for at least one of the
independent variables. All data should then be collected together and shared with the
group.
 Record everything you do in your logbook / google.doc. At a later date an
independent person, who is not in a position to talk to you, should be able to use your
logbook and your report to assess your work against the achievement standard
criteria and duplicate your investigation if they wish.
 If you change any aspect of your original method e.g. range of concentration, number
of experiments etc, note the reasons for change in your log book and discuss in your
final report.
 Continue until you have sufficient, accurate and relevant data to enable you to draw a
valid conclusion.
 You must use only the raw data that your group collects in any calculations.
 It is important to record all results even if they seem wrong. Possible reasons for
these unusual results should be considered in your discussion.
6. Process data (Individual)
 Finally, you must individually process the group data and write your report.
 Working for calculations must be shown
 The calculation procedure, formulae and any chemical equations should be clearly
set out to show how you obtained calculated answers. They should be described so
that an independent assessor could use the data to obtain the same answers.
Practical Invest 2014
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Where appropriate, graphs and tables of processed data should be used.
In general, calculated values should be stated with no more significant figures than
the least precise value used in the calculation.
7. Reporting (Individual)
Your report must include the following sections:
 A Purpose – which states the aim of the investigation or poses a question or
states an hypothesis.
 Relevant background Information – which could include reports on scientific
work related to the topic, experimental procedure and/or information about the
substances involved.
 Procedure - a method which is clear, concise and with sufficient detail so that
another person could repeat your procedures to produce the same results. This
must include a description of how samples are prepared, how significant
variables are controlled and a description of the analytical technique used. Any
modifications made to the method during the course of the investigation should
be included.
 Results –a summary of processed data in a systematic format with tables and
graphs where appropriate. A sample calculation using experimental data
obtained in the investigation will be included for each analytical procedure
(including standardisation of solutions).
 Conclusion – a clear statement of the outcome of your investigation. It must
be based on processed data and relate to the aim.
 Discussion – an evaluation of the whole investigation that considers:
a) An evaluation of the procedure used and how this allowed for the collection
of quality data; as well as any sources of error.
b) Reasons for any modifications made to the original method.
c) The accuracy and reliability of the data collected including discussion of
possible sources of error
d) Justifies how processed data supports conclusion.
e) Links conclusion to chemical principles and /or real life applications.
Bibliography – Your resources should be recorded as footnotes within your
report.
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Time frame:
12th June (W6):
Introduction / background information given out.
26th June (W8):
Background reading completed.
Choice of investigation must be finalised within your group
and the possible trend/pattern you are investigating is
recorded in your google.doc.
21st July (W1):
All details of your investigation must be finalised including
parts (3) to (4) of the planning requirements.
1st – 5th September (W7):
Lab trials carried out this week.
9th or 10th September (W8): A whole day will be devoted to the investigation so that you can
carry out the practical work.
14th October (W1):
Practical Invest 2014
All project reports must be submitted to your Chemistry teacher
BY the 8.45 am deadline. Logbooks must have the ownership
changed to your teacher and your editing rights removed.
3
Evidence/Judgements for Achievement
Evidence/Judgements for Achievement
with Merit
Evidence/Judgements for Achievement
with Excellence
The student carries out an investigation in
chemistry involving quantitative analysis.
They do this by:

carrying out an investigation into the
concentration of ………. leading to a
conclusion

keeping a logbook and producing a report
The student:
The student carries out an in-depth
investigation in chemistry involving
quantitative analysis. They do this by:

carry out a quality investigation into the
concentration of ………… leading to a
conclusion

keeping a logbook and produce a report
The student:
The student carries out a comprehensive
investigation in chemistry involving
quantitative analysis. They do this by:
 carry out and comprehensively evaluate
an investigation into the concentration of
…………. leading to a conclusion.
 keeping a logbook and produce a report
In addition to Merit, the student:

develops a purpose
includes a description of the procedure that
includes preparation of samples and the
analytical technique used
has five values for the independent variable
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includes a summary of the collected and
processed data
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standardises standard solution(s)

shows the mathematical steps used to
process the data

makes a valid conclusion relevant to the
purpose of the investigation

explains how the procedure used
contributed to the collection of quality data.
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makes a conclusion based on processed
data.
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carries out trials
controls significant variables
has five values for the independent variable
describes their method in sufficient detail to
enable it to be duplicated
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accurately processes the data and uses
appropriate significant figures and units
elaborates on reasons for any
modifications to procedure

justifies how the processed data supports
the conclusion(s)

evaluates the reliability of the data by
considering the procedure used and
sources of error

links the conclusion(s) to chemical
principles and/or real life applications.
Final grades will be decided using professional judgement based on a holistic examination of the evidence provided against the criteria in the
Achievement Standard.