1.
State what is meant by a volumetric flask.
[1 mark]
- makes a solution of known volume and concentration
JD SCIENCE
Scientific laboratory techniques and SOPs
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
2.
State what is meant by a burette.
[1 mark]
- delivers a variable volume to 0.05 cm³
3.
State what is meant by a balance.
[1 mark]
- measures mass
4.
State what is meant by pH measurement.
[1 mark]
- glass electrode, calibrated buffers
5.
State what is meant by chromatography.
[1 mark]
- separates mixtures
6.
State what is meant by spectroscopy.
[1 mark]
- interaction of light with matter
7.
State what is meant by microscopy.
[1 mark]
- magnifies a specimen
8.
State what is meant by centrifugation.
[1 mark]
- separates by density
9.
State what is meant by an SOP.
[1 mark]
- controlled method everyone must follow
10.
State what is meant by sample integrity.
[1 mark]
- correct ID, storage, chain of custody
11.
Pat is asked about a volumetric flask in a Pearson Laboratory Sciences paper.
(a) [2 marks]
- make up to the mark at eye level
(b) [3 marks]
- used for standards
12.
Pat is asked about a burette in a Pearson Laboratory Sciences paper.
(a) [2 marks]
- titration
(b) [3 marks]
- read the bottom of the meniscus
13.
Pat is asked about a balance in a Pearson Laboratory Sciences paper.
(a) [2 marks]
- analytical balances to 0.0001 g
(b) [3 marks]
- draft shield and tare
14.
Pat is asked about pH measurement in a Pearson Laboratory Sciences paper.
(a) [2 marks]
- rinse between samples
(b) [3 marks]
- store in KCl
15.
Pat is asked about chromatography in a Pearson Laboratory Sciences paper.
(a) [2 marks]
- TLC, HPLC, GC
(b) [3 marks]
- Rf or retention time
16.
Pat is asked about spectroscopy in a Pearson Laboratory Sciences paper.
(a) [2 marks]
- colorimetry, UV-Vis, IR, AA
(b) [3 marks]
- Beer–Lambert
17.
A 250 cm³ flask is used for 0.100 mol dm⁻³ NaOH. Mass of NaOH (M=40)?
[3 marks]
- Final answer: 1.00 g
18.
Beer–Lambert: A = εcl. A=0.60, ε=2000, l=1.0 cm. c?
[3 marks]
- Final answer: 3.0 × 10⁻⁴ mol dm⁻³
19.
Rf = 3.6 / 9.0
[3 marks]
- Final answer: 0.40
20.
A centrifuge runs at 3000 rpm for 10 min. Total revolutions?
[3 marks]
- Final answer: 30000
21.
Titres 24.10, 24.20, 24.15. Mean?
[3 marks]
- Final answer: 24.15 cm³
22.
A 10 cm³ pipette delivers 9.96 cm³. Percentage error?
[3 marks]
- Final answer: 0.40%
23.
Pat carries out a T-Level occupational task on laboratory techniques and SOPs. This is a typical Pearson required-practical style question.
(a) [2 marks]
- Independent: the factor being investigated
- Dependent: the measured result or quality check
(b) [2 marks]
- follow the SOP and keep other variables constant
- so the test is fair / only one variable is changed
(c) [2 marks]
- not recording the batch/lot number or operator ID
24.
Pat carries out writing or following an SOP for laboratory techniques and SOPs. This is a typical Pearson required-practical style question.
(a) [2 marks]
- Independent: a step in the method
- Dependent: whether the acceptance criteria are met
(b) [2 marks]
- same calibrated instrument
- so the test is fair / only one variable is changed
(c) [2 marks]
- skipping a verification check
25.
Pat carries out a COSHH / risk-assessment review for laboratory techniques and SOPs. This is a typical Pearson required-practical style question.
(a) [2 marks]
- Independent: hazard
- Dependent: control measure effectiveness
(b) [2 marks]
- same PPE and waste route
- so the test is fair / only one variable is changed
(c) [2 marks]
- using expired reagents or the wrong waste stream
26.
Pat carries out data review in a LIMS or quality log for laboratory techniques and SOPs. This is a typical Pearson required-practical style question.
(a) [2 marks]
- Independent: sample ID
- Dependent: result vs specification
(b) [2 marks]
- same calculation method
- so the test is fair / only one variable is changed
(c) [2 marks]
- transcription error between the instrument and the LIMS
27.
Compare a volumetric flask with pH measurement.
[4 marks]
- makes a solution of known volume and concentration
- glass electrode, calibrated buffers
- state one workplace implication
28.
Compare a burette with chromatography.
[4 marks]
- delivers a variable volume to 0.05 cm³
- separates mixtures
- state one workplace implication
29.
Compare a balance with spectroscopy.
[4 marks]
- measures mass
- interaction of light with matter
- state one workplace implication
30.
Compare pH measurement with microscopy.
[4 marks]
- glass electrode, calibrated buffers
- magnifies a specimen
- state one workplace implication
31.
Apply your knowledge of microscopy to this situation: light or electron
[3 marks]
- light or electron
32.
Apply your knowledge of centrifugation to this situation: balance the tubes
[3 marks]
- balance the tubes