Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Investigative Analytical Science > Tutorial 1 > Flashcards

Tutorial 1 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is accuracy?

A

The degree where the result of a measurement, calculation, or specification conforms to the correct value/standard.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is precision?

A

A measure of repeatability quotes as absolute standard deviation (SD) or relative standard deviation (RSD).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How can we show high accuracy and high precision?

A

All measurements in middle together.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How can we show low accuracy and high precision?

A

All measurements away from the middle but together.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can we show high accuracy and low precision?

A

All measurements near the middle but away from each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How can we show low accuracy and low precision?

A

All measurements away from the middle and away from each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the difference between a heterogeneous mixture and a homogenous mixture?

A

Homogenous mixture :
Intimately mixed on a small scale.

Heterogenous mixture :
Components not intimately mixed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some examples of a homogeneous mixture?

A 
Gases in atmosphere.
Ions in solution.
Very finely ground solid mixture.
One part of mixture has all components in same proportions.
Representative of whole.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some examples of a heterogeneous mixture?

A

Insoluble solid in liquid.
Stones and sand.
Rain falling.
Different portions with components in different proportions.
No small part is representative of whole.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is sample integrity important?

A

To make sure the correct samples is subjected to the right analysis.

The results go to the right place.

Nothing happens to sample that will endanger analysis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does integrity of the sample involve?

A

Ensuring correct sample.
Not changed.
Correct storage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How can we make sure it is the correct sample?

A

Correct labelling.
Correct information recording.
Powerful checking pathway.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How can we make sure nothing has changed in samples?

A

Correct packaging.

Sealed tightly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How can we make sure we storage samples correctly?

A

Keep cool in dark.
Free from air.
Contain acid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why might sample degradation during storage be a problem when analysing sample?

A

Result in increase/decrease of concentration will tested.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens to diazepam over time?

A

It degrades.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where do metal ions form insoluble hydroxides?

A

In neutral/basic solutions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When do solvents increase concentration?

A

When they evaporate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why should substances be kept in a desiccator?

A

To not absorb moisture by matrix and hydrolysed/dilute.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What happens to biological samples when they are not frozen at -80 degrees?

A

They degrade.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is light?

A

A source of energy.

22
Q

What can light promote when samples are not kept in amber bottles in the dark?

A

Reactions.

23
Q

Why is quality assurance/quality control important for chemical analysis?

A

It is a way of preventing mistakes/errors in analytical results.

Avoiding problems in solutions/to customers.

24
Q

What happens to every component of an analytical procedure?

A

It is tested regularly.

Records are kept.

25
Q

What are the factors that are tested regularly in analytical procedures?

A 
Volumetric flasks.
Pipettes.
Balances.
Instrumentation.
Method.
Calculation.
Powerful pathway/audit trail.
26
Q

What is the definition of a systematic error?

A

Not determined by chance.
Introduced by an inaccuracy.
Inherent in system.

27
Q

What can we do to the error if it is consistent and persistent?

A 
Adjust it.
Recovery check. 
Spike matrix with known amount.
Carry full sample prep and analysis many times.
Divide result by mean.
Get true amount.
28
Q

A copper penny contains 7.15% copper.
What is the mean and standard deviation of the group?
Data = 7.25, 7.45, 8.34, 7.41, 7.34.
Comment precision and accuracy.

A 
Average = 7.56.
Standard deviation = 0.44
RSD = 5.82%.
Not really accurate.
Not really precise.
29
Q

What does integrity of the sample involve?

A

Ensuring correct sample identity.

Ensuring nothing changed.

30
Q

Which 3 factors ensure it is the correct sample?

A

Traceability.
Good record keeping.
Secure storage.

31
Q

Which are the 4 factors that help to ensure the integrity of an analytical procedure and its outcome?

A
  1. Chain care of sample and correct labelling.
  2. Secure storage.
  3. Cleanliness.
  4. Correct storage.
32
Q

How can we make sure about sample’s integrity with chain care of the sample and correct labelling?

A

Powerful pathway.

Sign in and out.

33
Q

How can we make sure about sample’s integrity with secure storage?

A

Avoiding tampering.

Locked doors, cupboard, fridges.

34
Q

How can we make sure about sample’s integrity with cleanliness?

A

Avoid contamination.
Day to day cleaning.
Deep regular cleans.

35
Q

How can we make sure about sample’s integrity with correct storage?

A 
Prevent chemical reactions.
Sample did not change.
Cold storage.
Under inert atmosphere.
In dark.
36
Q

What happens at -80 degrees?

A

Everything stops for a long time.

Samples are not degraded.

37
Q

What happens when samples come in contact with water?

A

Reaction stops.

38
Q

Where does the sample’s storage depend?

A

On sample’s nature.

39
Q

How do chemists storage solutions normally?

A

Freeze.
Evaporate.
Store in freezer.

40
Q

What does assurance help?

A

Quality of work.

High standards.

41
Q

What does everything in the lab need to be?

A

Accredited.

42
Q

How can material and processes in lab be accredited?

A

Regularly testing.

43
Q

What happens to the out of day material?

A

Not used.

44
Q

What happens to the flasks when they dry in the oven?

A

Change sheep.

Change scale measurement.

45
Q

What must we do to all the used flasks?

A

Wash them.

46
Q

What does acetone do?

A

Soluble in water.
Evaporates.
Cleans flasks.

47
Q

What must we do in the laboratories?

A

Everything in best possible way.

48
Q

Why is RSD = 5.82% not accurate?

A

Far from 7.15.

49
Q

How do we know a process is more precise based on RSD?

A

< 2% = more precise.

> 2% = less precise –> reject.

50
Q

How do we call values really far from everything else?

A

Outliners.

51
Q

What must we know before we enter the laboratory?

A

Samples.
People.
Data.
Everything.

Investigative Analytical Science (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions