Vet Labs Sat 2 Rev

Question 1

Differentiate between precision and accuracy

Answer 1

Accuracy refers to how close a measurement is to the true or accepted value. Precision refers to how close measurements of the same item are to each other

Question 2

Comprehend the significance of significant figures in reporting measurement results.

Answer 2

By using significant figures, we can show how precise a number is.

Question 3

Determine the number of significant figures in a measurement.

Answer 3

1. 0.00721800
2. 1690020.00

Question 4

Provide an example of how to improve the repeatability of a measurement.

Answer 4

1. Properly Label Everything.
2. Avoid Expired Reagents or Perform
   Quality Control Tests.
3. Design Your Experimental Protocols
   in Detail.
4. Include Appropriate Controls and
   Practices.
5. Assign Work Appropriately.

Question 5

Understand the concept of measurement error.

Answer 5

refers to the difference between the observed value (the result of measurement) and the actual value of what we are measuring.

Question 6

List and know the seven base units of the International System of Units (SI).

Answer 6

• Length - meter (m)
• Time - second (s)
• Amount of substance - mole (mole)
• Electric current - ampere (A)
• Temperature - kelvin (K)
• Luminous intensity - candela (cd)
• Mass - kilogram (kg)

Question 7

Convert measurements between different units (e.g., kilometers to meters, milliliters to liters).

Answer 7

0.078km –> m

78000m –> km

782ml –> L

120L –> ml

Question 8

Know the primary purpose of titration.

Answer 8

to determine the concentration of a substance by reacting that substance with another substance of known concentration in a reaction.

Question 9

The process of performing titration

Question 10

Endpoint

Answer 10

The point during a titration when an indicator shows that the amount of reactant necessary for a complete reaction has been added to a solution.

Question 11

Importance of Endpoint

Answer 11

Allows researchers to obtain the precise measurement of the analyte concentrations in solution

Question 12

Define repeatability in the context of laboratory measurements.

Answer 12

A measure of the ability of the method to generate similar results for multiple preparations of the same sample.

Question 13

Describe the purpose of performing tests in a laboratory setting.

Answer 13

The purpose of performing tests in a laboratory setting is to ensure the results are accurate, there is no contamination between chemicals and all possible risks are minimised (PPE)

Question 14

How does titration help in determining the concentration of an unknown solution?

Answer 14

Titration helps in determining the concentration of an unknown solution by adding the titrant (known solution) placed in the buret to a known quantity of the analyte (the unknown solution) until the reaction is complete. Knowing the volume of titrant added allows the determination of the concentration of the unknown.

Question 15

Explain the role of an indicator in a titration process.

Answer 15

To identify the equivalence or the end point of a reaction where pH change occurs.

Question 16

Describe a scenario where titration is used in your job role.

Answer 16

Product development and quality control - In food processing, acid or base titration determines the acidity of fruit juice.

Question 17

Describe a pre-use safety check you would perform on laboratory equipment. (e.g pick a piece of equipment and describe the checks you would use)

Answer 17

possible general pre-use safety checklist for lab equip

• check for remaining solids (e.g residue on glass)
• check for glass chippings
• check for cracks
• check for general damage
• check for possible missing parts
• check for accuracy (volumetric flask) idk

Question 17

How can improper equipment checks affect test results?

Answer 17

• Provides false readings
• inaccurate measurements
• spill/chemical contamination

Question 18

How can you minimise the uncertainty in a measurement?

Answer 18

Calibrate your instruments and take multiple measurements to average out. Reduce random errors by keeping conditions stable and repeating tests to spot and remove odd results.

Question 19

What role does calibration play in controlling measurement uncertainty?

Answer 19

Ensures that the instruments produce results that reflect reality as closely as possible

Question 20

Explain the concept of traceability in the context of laboratory work.

Answer 20

Traceability is how we know that a measurement is accurate.
- involves linking the value that we say we have achieved, to an international measure.
- involves comparisons in measurements and considers how many steps are involved.

Question 21

Why is legal traceability important in laboratory testing?

Answer 21

Credibility of results can have far-reaching consequences in terms of public health, safety and in legal judgments based on laboratory reports

Question 22

How do you ensure traceability of a sample from collection to reporting?

Answer 22

Implement a Secure Database or Electronic System

Question 23

What constitutes an unexpected or unusual result in a laboratory test?

Answer 23

Results that lie outside the laboratory reference ranges

Question 24

What procedures should you follow if you encounter an unusual result?

Answer 24

- check your data and methodology for errors - Fix errors - rinse and repeat the experiment

Question 25

What are the procedures for coding and entering data in a laboratory setting?

Answer 25

- Record in log book - electronically - record straight away - store in multiple locations

Question 26

How do you maintain and file records securely?

Answer 26

Have a secure off-site storage location, which may include cloud storage.

Question 27

What steps should you take to rectify mistakes in data entry?

Answer 27

- Identify the source and scope of the error. - Choose the best method to correct the error. - Test and verify the correction. - Document and report the correction. - Monitor and evaluate the correction.

Question 28

What is the difference between quantitative data and qualitative data in the context of laboratory measurements?

Answer 28

Quantitative data is data involving numbers, usually involves calculating mass, volume, area etc Qualitative data is data involving words and it is used to describe things, usually involves colours, smell, texture etc

Question 29

Example of a laboratory test that yields quantitative data and another that yields qualitative data.

Answer 29

Yields quantitative data: blood glucose levels Yields qualitative data: colour of different metals burning in fire

Question 30

Define random error and provide an example of how it might occur in a laboratory setting.

Answer 30

Definition: An error in measurement caused by factors which vary from one measurement to another. Example: measuring in a beaker then transferring the liquid to a measuring cylinder - idk

Question 31

How can operator error and equipment error impact the reliability of test results? Provide an example for each.

Answer 31

Both operator error and equipment error can impact the reliability of test results by providing false information about the test, an example is a balance that is faulty therefore providing false weigh of ingredients.