BTEC Level 3 Certificate in Applied Science
Unit 4 Scientific Practical Techniques
ScientificTechniques
Assignment brief – QCF BTEC
Assignment front sheet: 4.2 Scientific Techniques
Learner name
Date issued
Target
Assessor name
D*
Mrs N Turner-Smith
Completion date
Submitted on
Unit number and title
Unit 4: Scientific Practical Techniques
Assignment title
Scientific Techniques
In this assessment you will have opportunities to provide evidence against the following criteria.
Criteria
reference
To achieve the criteria the evidence must show that the
learner is able to:
Task
No.
Evidence
Demonstration use of scientific techniques to separate
substances.
P2
Paper Chromatography of amino acids
1
Distillation of ink and water
2
Precipitation reactions
3
Synthesis of starch from an enzyme using centrifugation
4
Crystallisation with filtering
5
Drying
6
Extraction of iodine from seaweed (solvent extraction)
7
Gel electrophoresis of food dye
8
Recrystallisation of benzoic acid and testing its purity.
11
Estimate the purity of samples using scientific
techniques
P3
Estimating the purity of aspirin using titration
9
Estimating the purity of aspirin using Paper Chromatography
10
Recrystallisation of benzoic acid and testing its purity.
11
Describe the factors that influence purity
Estimating the purity of aspirin using titration
9
Estimating the purity of aspirin using Paper Chromatography
10
Recrystallisation of benzoic acid and testing its purity.
11
M2
Evaluate the accuracy of the measurements taken.
Estimating the purity of aspirin using titration
9
Estimating the purity of aspirin using Paper Chromatography
10
Recrystallisation of benzoic acid and testing its purity.
11
D2
1
BTEC Level 3 Certificate in Applied Science
Unit 4 Scientific Practical Techniques
ScientificTechniques
Learner declaration
I certify that the work submitted for this assignment is my own and research sources are fully acknowledged.
Learner signature:
Date:
2
BTEC Level 3 Certificate in Applied Science
Unit 4 Scientific Practical Techniques
ScientificTechniques
Assignment 4.1 brief
Qualification
BTEC Level 3 Certificate in Applied Science
Unit number and title
Unit 4: Scientific Practical Techniques
Start date
Deadline
Assessor name
Assignment title
Mrs N Turner-Smith
Scientific Techniques
The purpose of this assignment is to demonstrate an understanding of the use of techniques used to separate and
analyse substances.
Scenario
Competency in carrying out chemical experiments develops over time with practice. As a junior technician with a
large chemical supplier, you must demonstrate that your skills are improving by carrying out a significant number of
practical activities using separation techniques.
Task 1
P1 Carry out quantitative and qualitative analytical techniques
Using the method provided carry out paper chromatography to identify unknown samples of amino acids. You will
need to calculate the Rf values for the unknown samples and identify which amino acids are present. Ensure that
you show all of your workings and submit an observation sheet for the practical.
Due date:
Task 2
This provides evidence for P2 (part)
P2 Carry out quantitative and qualitative analytical techniques
You will be shown a demonstration on the process of distillation. Following the demonstration complete the
worksheet where you will be required to label the equipment and explain how the separation method works.
Due date:
Task 3
This provides evidence for P2(part)
P2 Carry out quantitative and qualitative analytical techniques
You are going to carry out a number of precipitation reactions including;
1.
2.
Silver Nitrate with Sodium Chloride
Iron Sulfate with Sodium Hydroxide
3.
Barium chloride with Hydrochloric Acid
4.
Copper Sulfate with Sodium Hydroxide
For each of the tests above you need to determine whether a precipitate is formed, the colour of the precipitate and
the chemical equation showing the reaction. Ensure that you submit an observation sheet for the practical.
Due date:
Task 4
This provides evidence for P2(part)
P2 Carry out quantitative and qualitative analytical techniques
You are going to carry out a practical using a centrifuge where you will be synthesising starch from an enzyme
found in potato tubers. You will follow a given method. Following the practical write a brief explanation of how a
centrifuge works and submit an observation sheet for the practical.
Due date:
This provides evidence for P2(part)
3
BTEC Level 3 Certificate in Applied Science
Task 5
Unit 4 Scientific Practical Techniques
ScientificTechniques
P2 Carry out quantitative and qualitative analytical techniques
You will explore how salt deposits are formed. You will investigate the difference in crystal size dependent on the
rate of evaporation of the water. You will follow a given method and will demonstrate the separation techniques of
crystallisation and filtering. Ensure that you record your results and complete the worksheet. Make sure that you
submit an observation sheet along with your worksheet.
Due date:
Task 6
This provides evidence for P2(part)
P2 Carry out quantitative and qualitative analytical techniques
You are going to prepare a sample of copper carbonate and use separation techniques, including precipitation,
filtration and drying. You will follow a given method and complete a worksheet on your findings. Make sure that
you submit an observation sheet along with your worksheet.
Due date:
Task 7
This provides evidence for P2(part)
P2 Carry out quantitative and qualitative analytical techniques
You are going to watch a demonstration of a solvent extraction. Your teacher will use the method to extract iodine
from seaweed. Following the observation complete the worksheet to assess your understanding of the technique.
Due date:
Task 8
This provides evidence for P2 (part)
P2 Carry out quantitative and qualitative analytical techniques
You are going to carry out the separation technique of gel electrophoresis. You will be given an unknown sample of
food dye and you will need to determine the colours present by comparing against a standard. Make sure that you
submit an observation sheet along with photographs of your gel.
Due date:
Task 9
This provides evidence for P2 (part)
P3 Estimate the
purity of samples
using scientific
techniques
M2: Describe the
factors that influence
purity
D2: Evaluate the accuracy of the
measurements taken.
In this experiment you will determine the percentage purity of aspirin in two different strengths of over the counter
aspirin tablets by performing a titration with sodium hydroxide. You will then calculate the percentage of aspirin
you calculated by titration and compare this to the percentage stated by the manufacturer. You will then complete
the worksheet describing how impurities can arise and evaluate the accuracy of your technique. Ensure that you
submit an observation sheet, along with your calculations and your worksheet.
.
Due date:
This provides evidence for P3, M2 and D2 (part)
4
BTEC Level 3 Certificate in Applied Science
Unit 4 Scientific Practical Techniques
ScientificTechniques
P3 Estimate the purity of
M2: Describe the factors
samples using scientific
that influence purity
techniques
In this experiment you will determine the purity of aspirin in three different samples.
Task 10
D2: Evaluate the accuracy
of the measurements taken.

Sample one – Synthesised aspirin (this stage will be carried out by the technicians)

Sample two – Re-crystallised aspirin (this stage will be carried out by the technicians)

Sample three – a Known sample of aspirin
You will be using the process of chromatography and calculate the Rf values of each of your samples. You will then
complete the worksheet describing how impurities can arise and evaluate the accuracy of your technique. Ensure
that you submit an observation sheet, along with your calculations and your worksheet.
Date Due:
Task 11
This provides evidence for P3, M2 D2 (part)
P2 Carry out
quantitative and
qualitative analytical
techniques
P3 Estimate the purity of
samples using scientific
techniques
M2: Describe the factors
that influence purity
D2: Evaluate the accuracy
of the measurements
taken.
You are going to carry out a recrsytallisation of benzoic acid following a given method. Following your procedure you
are going to estimate its purity by using the melting point technique. You will calculuate the percentage of benzoic
acid that you recovered. You will then complete the worksheet describing how impurities can arise and evaluate the
accuracy of your technique. Ensure that you submit an observation sheet, along with your calculations and your
worksheet.
Due date:
This provides evidence for P2,P3,M2 and D2 (part)
Evidence checklist
[Summarise evidence required, e.g. ‘leaflet’, ‘presentation notes’ etc.]
[tick
boxes]
Paper Chromatography of amino acids, calculations and observation record
Distillation of ink and water and completed worksheet
Precipitation reactions worksheets and observation record
Synthesis of starch from an enzyme using centrifugation observation record and explainination of the
separation technique
Crystallisation with filtering, worksheet and observation record
Drying worksheet and observation record
Extraction of iodine from seaweed (solvent extraction) worksheet
Gel electrophoresis of food dye worksheet and observation record.
Estimating the purity of aspirin using titration worksheet and observation record
Estimating the purity of aspirin using chromatography worksheet and observation record
Recrystallisation of benzoic acid and testing its purity worksheet and observation record
5
BTEC Level 3 Certificate in Applied Science
Unit 4 Scientific Practical Techniques
ScientificTechniques
Sources of information
Annets F, Foale S, Hartley J, Hocking S, Hudson L, Kelly T, Llewellyn R, Musa I and Sorensen J – BTEC Level 3
National Applied Science Student Book (Pearson, 2010) ISBN 9781846906800
Coyne G S – The Laboratory Companion: A Practical Guide to Materials, Equipment and Technique
(John Wiley & Sons, 2005) ISBN 9780471780861
Dean J R et al – Practical Skills in Chemistry (Prentice Hall, 2001) ISBN 9780130280022
Lawn R and Prichard E – Practical Laboratory Skills Training Guide: Measurement of Mass (The Royal Society of
Chemistry, 2003) ISBN 9780854044634
Prichard E and Lawn R – Practical Laboratory Skills Training Guide: Measurement of Volume (The Royal Society of
Chemistry, 2003) ISBN 9780854044689
A virtual laboratory
This brief has been verified as being fit for purpose
Assessor
Mrs N Turner-Smith
Signature
Internal verifier
Signature
Date
Mrs C Helim
Date
6
BTEC Level 3 Certificate in Applied Science
Unit 4 Scientific Practical Techniques
ScientificTechniques
Assessor's comments
Qualification
BTEC Level 3 Certificate in Applied
Science
Assessor
name
Unit number and
title
Unit 4; Scientific Practical
Techniques.
4.2: Scientific Techniques
Learner
name
Criteria
reference
Mrs N Turner-Smith
To achieve the criteria the evidence must show that the learner is
able to:
P3
Use scientific techniques to separate substances including precipitation;
crystallisation; filtration; drying; distillation; solvent extraction; chromatography;
electrophoresis and centrifugation
Use scientific techniques to assess the purity of different substances
M2
Discuss the factors influencing purity,
D2
Evaluate the accuracy of all the methods chosen to estimate purity.
P2
Achieved?
Learner feedback
Assessor feedback
Assessor signature
Date
Learner signature
Date
7