FT: Q2 Flashcards

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1
Q

A method to measure how much a chemical substance absorbs light by measuring the intensity of light as a beam passes through sample solution

A

Spectrophotometry

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2
Q

One of the most frequently used tools to determine both the presence and concentration of dissolved chemicals

A

Spectrophotometer

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3
Q

Measures the amount of photons absorbed after it passes through a sample solution

A

Spectrophotometer

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4
Q

4 main applications of spectrophotometry

A
  1. Qualitative analysis
  2. Quantitative analysis
  3. Enzyme assay
  4. Molecular weight identification
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5
Q

Instrument designed to detect the amount of light energy that is absorbed or transmitted by molecules dissolved in a solution

A

Spectrophotometer

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6
Q

Classification of a spectrophotometer that uses light over the ultraviolet and visible range

A

UV-visible spectrophotometer

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7
Q

Classification of a spectrophotometer that uses light over the infrared range

A

IR spectrophotometer

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8
Q

A solution sample that absorbs light over all visible ranges appears […]

A

black, in theory

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9
Q

A solution sample that transmits light over all visible ranges appears […]

A

white

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10
Q

A solution sample that absorbs a specific wavelength appears […]

A

as its complementary color

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11
Q

The basic structure of spectrophotometers

A
  • Light Source
  • Collimator
  • Monochromator
  • Wavelength Selector
  • Cuvette
  • Photoelectric Detector
  • Digital Display
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12
Q

An instrument that produces a desired range of wavelength of light

A

Spectrometer

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13
Q

An instrument that detects the amount of photons absorbed and then sends a signal to a digital display

A

Photometer

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14
Q

A lens that transmits a straight beam of light

A

Collimator

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15
Q

A prism that splits the beam of light into several component wavelengths

A

Monochromator

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16
Q

A wavelength selector that transmits only the desired wavelengths

A

Slit

17
Q

The amount of photons that goes through the cuvette and into the detector is dependent on […]

A

the length of the cuvette and the concentration of the sample

18
Q

The fraction of light that passes through the sample

A

Transmittance (T)

19
Q

The amount of light unable to pass through a sample is measured as the […]

A

absorbance value

20
Q

Transmittance equation

A

T = It / Io

where:
- It is the light intensity after the beam of light passes through the cuvette
- Io is the light intensity before the beam of light passes through the cuvette

21
Q

Absorbance Equation

A

A = -log(T)

22
Q

States that there is a linear relationship between the absorbance and the concentration of a sample

A

Beer-Lambert Law

23
Q

Beer-Lambert Equation

A

A = εcl

where:
- A is the absorbance
- ε is the molar absorption coefficient (M^-1cm^-1)
- c is the molar concentration (M)
- l is the optical path length (cm)

24
Q

An instrument used to measure absorbance and conduct quantitative analysis at the visible light

A

VIS Spectrophotometer

25
Q

Bacterial cell density can be determine at how many nanometers?

A

600 nm

26
Q

An instrument used to measure the material of absorbance and quantitative analysis at the visible or ultraviolet light

A

UV-VIS Spectrophotometer

27
Q

A type of UV-VIS spectrophotometer suitable for measuring absorbance or light transmittance at a given wavelength, requiring high stability of the light source and detector

A

UV-VIS Single Beam

28
Q

A type of UV-VIS spectrophotometer that utilizes two monochromators

A

UV-VIS Double Beam

29
Q

The most commonly used spectral region of organic compounds

A

Infrared Spectrum (>760 nm)

30
Q

A type of spectrophotometry mainly applied to detect trace components in the sample analysis

A

Atomic Absorption

31
Q

Generation Time equation

A

GT = t / 3.3 log(b/B)

where:
- t is the time interval between measurements b and B
- B is the initial population
- b is the population after time t

32
Q

The two most common classroom methods to determine bacterial growth

A
  • Standard Plate Count
  • Turbidimetric Measurement