Spectrophotometry, Atomic & Mass Spectroscopy | Verified
Questions & Answers | Graded A+
1. How do the units of concentration differ from the units of solubility?
The units of concentration are per volume of solvent while the units of
solubility are per volume of solution.
The units of concentration are per volume of solution while the units
of solubility are per volume of solvent.
The units are the same (i.e. both mass per volume).
2. What is the numerical value represented by the prefix 'femto-'?
10^-6
10^-15
10^-12
10^-9
3. What does the Heisenberg Uncertainty Principle indicate about the
relationship between the lifetime of an excited state and energy uncertainty?
The longer the lifetime of the excited state, the more certain the
energy.
The lifetime of the excited state has no effect on energy uncertainty.
Energy is always certain regardless of the excited state.
The shorter the lifetime of the excited state, the more uncertain the
energy.
4. Interference in atomic absorption spectrophotometry caused by differences
in viscosity is called:
, Matrix effect
Absorption interference
Ionization interference
Quenching
5. If a researcher is conducting UV spectroscopy and uses a glass cuvette
instead of a quartz cuvette, what potential issue might arise?
Improved sensitivity of the measurements.
Faster analysis times due to lower light scattering.
No issues, as glass cuvettes are suitable for all wavelengths.
Inaccurate absorbance readings due to light absorption by the
glass cuvette.
6. Light behaves as though it consists of discrete particles called _.
protons
photons
electrons
neutrons
7. The difference between Q and Ksp is
no difference.
Q is greater than Ksp.
Ksp is greater than Q.
Q is the value of the product at equilibrium and Ksp is the value of the
product under any condition.
, Ksp is the value of the product at equilibrium and Q is the value of
the product under any condition.
8. In a laboratory experiment, you have an unknown concentration of acid that
reacts too quickly for direct titration. Which titration method would you
choose and why?
Direct titration, because it is the simplest method.
Back titration, because it allows for the measurement of the excess
reagent after the reaction.
Indirect titration, because it is always more accurate.
No titration is needed, as the concentration can be estimated.
9. What does the Henderson-Hasselbalch equation relate to in analytical
chemistry?
Concentration of solutes and solvents
Volume and mass of reactants
Temperature and pressure of a solution
pH, pKa, and the ratio of concentrations of deprotonated and
protonated forms
10. Which one of the following ionization techniques lead to fragmentation?
Fast Atom Bombardment (FAB)
Plasma Desorption
Electrospray Ionization (ESI)
Chemical Ionization (CI)
Matrix Assisted Laser Desorption Ionization (MALDI)
, Electron Impact (EI)
11. Which of the following defines precision and accuracy?
Measurements that are precise are never accurate.
Measurements cannot be both precise and accurate.
Precision is how close measurements are to one another; accuracy
is how close they are to correct
Accuracy is how close measurements are to one another; precision is
how close they are to correct.
12. The concentration of ions in water is often reported in PPM. PPM stands for:
parts per million
parts per millionth
parts per milla
parts per millisecond
13. If a chemist is using spectroscopy to analyze a sample, what type of
information might they obtain about the sample?
Information about the sample's molecular structure and
composition.
Information about the sample's physical state only.
Information about the sample's temperature and pressure.
Information about the sample's color and appearance.
14. If a sample has a high viscosity, how might this matrix effect influence the
results of atomic absorption spectroscopy?