PRELIM 01 - Instrumentation

Question 1

Measures the hydrogen ion concentration and the pH of an unknown solution

Answer 1

pH meter

Question 2

Most modern pH meters also have a __________ which allows automatic temperature corrections since pH may vary relative to the temperature

Answer 2

Temperature probe

Question 3

A pH meter is equipped with __________ and __________

Answer 3

Glass electrode, Reference electrode

Question 4

An electrode that consists of a thin, pH sensitive glass membrane, the inside of which contains a solution with constant concentration of hydrogen ions

Answer 4

Glass electrode

Question 5

Most common reference electrode

Answer 5

Calomel electrode

Question 6

An electrode that incorporates a salt bridge filled with a saturated potassium chloride (KCl) solution

Answer 6

Calomel electrode

Question 7

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

Answer 7

Spectrophotometry

Question 8

Instrument used in spectrophotometry

Answer 8

Spectrophotometer

Question 9

A spectrophotometer that makes the sample absorb light in the visible and near ultraviolet region of the electromagnetic spectrum

Answer 9

Ultraviolet-Visible (UV-VIS) spectrophotometer

Question 10

Are assays used to measure the amount of light transmitted through a sample at a given wavelength

Answer 10

Colorimetric assays

Question 11

UV/Vis spectrophotometer - Ultraviolet range

Answer 11

185-400 nm

Question 12

UV/Vis spectrophotometer - Visible range

Answer 12

400-700 nm

Question 13

IR spectrophotometer - Infrared range

Answer 13

700-15,000 nm

Question 14

7 essential parts of UV/Vis spectrophotometer

Answer 14

White light source, Monochromator, Sample compartment, Detector, Read out device, Tungsten lamp, Deuterium lamp

Question 15

Disperses light into its component’s wavelengths

Answer 15

Monochromator

Question 16

Holds the transparent tube or cell containing the sample

Answer 16

Sample compartment

Question 17

Measures the amount of light transmitted

Answer 17

Detector

Question 18

Device that displays the reading

Answer 18

Read out device

Question 19

Used as a light source in the visible region

Answer 19

Tungsten lamp

Question 20

Used as a light source in the ultraviolet region

Answer 20

Deuterium lamp

Question 21

The ratio of the intensity of the transmitted light to the incidence light

Answer 21

Transmittance

Question 22

Refers to the amount of light absorbed by a sample

Answer 22

Absorbance

Question 23

Law that is involved in the determination of the concentration of the absorbing species in the analyte solution

Answer 23

Beer-Lambert’s law

Question 24

Law that states that the intensity of transmitted light decreases exponentially as any one of these factors increases

Answer 24

Beer’s law

Question 25

Is a measure of how strongly a solution absorbs light in a particular wavelength

Answer 25

Molar extinction coefficient

Question 26

Process used to separate or concentrate materials suspended in a liquid medium using the effect of gravity on the particles in suspension

Answer 26

Centrifugation

Question 27

Fictitious force; peculiar to a particle moving on a circular path

Answer 27

Centrifugal force

Question 28

Device used to separate the particles in a solution according to their size, shape, density, or the viscosity of the medium and the rotor speed

Answer 28

Centrifuge

Question 29

Spectrophotometer that offers 5 nm spectral split and has a wavelength range of 200-1100 nm

Answer 29

GENESYS 5 spectrophotometer

Question 30

Spectrophotometer used to measure UV/Vis absorbance from 200 to 1000 nm on 96 to/or 384-well microcplates

Answer 30

Multiskan go microplate spectrophotometer

Question 31

Allows smaller sample volume (Microliter)

Answer 31

Microplate

Question 32

The Beer-Lambert's law is most accurate between the absorbance of __________ to __________

Answer 32

0.05 to 0.70

Question 33

Using a multiskan go microplate spectrophotometer, one must incubate up to _____ and shake the microplate

Answer 33

45°C

Question 34

A spreadsheet like __________ may be used to generate a standard calibration curve

Answer 34

Microsoft Office Excel

Question 35

4 applications of UV/Vis spectrophotometer

Answer 35

Reaction kinetics, Quantitation, pKa determination, DNA structural information

Question 36

4 things to avoid on or inside the cuvette because it diminishes the accuracy of the reading

Answer 36

Formation of bubbles, Turbidity, Fingerprints, Condensation