Brainscape's Knowledge GenomeTM

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


See full index

Instrumental Analysis > Chapter 1 - Intro to Spectroscopy > Flashcards

Chapter 1 - Intro to Spectroscopy Flashcards

1
Q

What is Spectroscopy?

A

Uses electromagnetic radiation (EM) to analyze chemical samples for properties like concentration, structure, etc.

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

What is a Spectrophotometer?

A

An instrument that measures how much radiation passes through the sample (i.e. the transmission of light).

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

What is the Wavelength Spectrum for Visible Light?

A

390 nm to 760 nm

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

What is the Wavelength Spectrum for UV Light and beyond?

A

< 390 nm

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

What is the Wavelength Spectrum for IR and beyond?

A

> 760 nm

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

What is the Order of Colors in Visible Light?

A

ROY G BIV or Red, Yellow, Green, Blue, Indigo, and Red (Highest energy to lowest energy)

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

What is the Relationship between Energy and Wavelength?

A

Higher energy = shorter wavelength

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

What is the Order of All Electromagnetic Radiations?

A

Raging Martians Invade Venus Using X-Ray Guns or Radio, Micro, IR, Visible, UV, X-ray, and Gamma (Lowest energy to highest energy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the Properties of Photons?

A

Wave and Particle (Particles that travel like a wave)

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

What does Electromagnetic Radiation Consist of?

A

Photons, which are small packets of energy

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

What is a Wavelength?

A

The length between two zero points

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

What is Amplitude?

A

The height of a wave

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

What is a Period?

A

Equivalent to a wavelength in the context of time

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

What is a Peak?

A

Equivalent to amplitude in the context of time

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

What is the Equation for Frequency?

A

1/T (T = period)

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

What is the Equation for Speed?

A

Wavelength/Period

Frequency x Wavelength

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

What is Planck’s Equation?

A

E = nhv
#photons x 6.63*10^-34 x frequency

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

How are Bonds affected from Radio to Gamma Radiation?

A

Radio: Nothing
Microwave: Rotation
IR: Vibration
Visible/UV: Electron excitation
UV: Bond breaking and ionization
Gamma: Same or worse than UV

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

What are the Components of a Single-Beam Spectrophotometer

A
  1. Radiation Source
  2. Wavelength Selector (monochromator): prism or diffraction grating
  3. Sample (in cuvette)
  4. Radiation Detector
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the Types of Absorption Spectroscopy?

A
  1. Atomic Absorption Spectroscopy (AAS): Analyzes atoms and elements (i.e. how much calcium in blood)
  2. UV/Visible Absorption Spectroscopy: Detects molecular content and concentration (i.e. proteins and other chemicals)
  3. IR Spectroscopy: Used often to determine chemical structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is R^2?

A

The correlation coefficient, which analyzes how close your data points are to a linear function

22
Q

What is P0?

A

Initial beam or amount of radiation

23
Q

What is P?

A

Emergent beam or final amount of radiation

24
Q

Besides Absorption, How is Radiation Lost?

A
  1. Through reflection on both sides of the cuvette
  2. Scattering due to molecule being large
25
Q

Why is a Blank Used?

A

To account for losses due to reflection and scattering. This way, you can subtract that from each sample and normalize

26
Q

What is Transmittance?

A

How much radiation passed through the sample

T = P/P0

%T = 100 x T

27
Q

What is the Relationship between Absorbance and Transmittance?

A

As absorbance increases, transmittance decreases

28
Q

What is Absorbance?

A

How much radiation was absorbed by the sample

A = log10 (P0/P)

A = -log10 (T)

A = log10 (100/%T)

A = 2 - log10 (%T)

29
Q

What does a Major Jump in Absorbance for a Given Wavelength Indicate?

A

That wavelength is absorbed most by the sample and indicates valence electrons going from ground to excited states

30
Q

What is Beer’s Law?

A

A = molar absorptivity x path length x sample concentration

31
Q

What are the Types of Emission Spectroscopy?

A

Fluorescence Spectroscopy: Uses high energy photons to excite low energy photons and measures how much energy they emit

32
Q

What are the Types of Scattering Spectroscopy?

A
  1. X-ray crystallography: Provides information about bond lengths, atomic positions, and chemical structure
  2. Raman Spectroscopy
33
Q

What is an Analyte?

A

The substance being analyzed

34
Q

What is Analysis?

A

Gives you chemical or physical info about components in the sample

35
Q

What is a Matrix?

A

All other components except the analyte (i.e. salts, etc)

36
Q

What is Determination?

A

An analysis to find the concentration, identity, or other properties of the analyte

37
Q

What is Measurement?

A

Experimental determination of an analyte’s properties

38
Q

What is Technique?

A

The principle that can be used to analyze a sample (i.e. you can use IR spectroscopy to determine a chemical’s functional groups)

39
Q

What is a Method?

A

The application of a technique to analyze a sample (i.e. you can use AAS to determine the amount of lead in blood)

40
Q

What is a Procedure?

A

Directions outlining how to analyze a sample

41
Q

What is a Protocol?

A

Guidelines detailing a procedure that must be followed if the agency specifying the protocol is to accept the analysis

42
Q

What are Total Analysis Techniques?

A

Signal is proportional to the absolute amount of analyte

43
Q

What are Concentration Techniques?

A

Signal is proportional to the relative amount of analyte

44
Q

What is Accuracy?

A

A comparison of the experimental and expected values

High Accuracy: 1% error

Moderate Accuracy: between 1% and 5% error

Low Accuracy: greater than 5% error

45
Q

What is Precision?

A

How close a result is each time the same procedure is run

46
Q

What is sensitivity?

A

A method’s ability to distinguish between 2 samples with different amounts of an analyte

46
Q

What is a Detection Limit?

A

The smallest amount of analyte needed to get a confident result

47
Q

What is Selectivity?

A

How well a method can separate an analyte and interfering substances (i.e. background noise)

48
Q

What is a Robust Method?

A

A method that can be applied to analytes in a variety of matrices

49
Q

What is a Rugged Method?

A

One that is not affected by changes in experimental conditions (e.g. temperature, reaction time, etc)

50
Q

What does a Blank do?

A

Reveals background signal that you can account for in your analysis

51
Q

What is Calibration?

A

Ensuring that a signal measured by an instrument is correct

A standard known to produce an exact signal is used

The instrument used should be calibrated over a broad range that includes your expected value (e.g. pH meters are calibrated using pH buffer standards of 4,7, and 10. If you expected your pH to be 8, then you should include the 7 and 10 standards.)

Instrumental Analysis (1 decks)

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