CHEM 162 EXPERIMENT 2 ELECTROCHEMISTRY
EXAM SCRIPT 2026 TEST PAPER QUESTIONS
AND SOLUTIONS GRADED A+
◉ EXPT1:: If you don't want to go the trouble of preparing solutions,
measuring absorbances, plotting a Beer's law graph, and calculating
molar absorptivity from the slope of the graph, the value of the
molar absorptivity, epsilon, can be looked up in the chemical
literature. Answer: false
◉ EXPT1:: When preparing an acid solution by dilution of the
concentrated acid, Answer: add water to the volumetric flask first,
then add the concentrated acid
◉ EXPT1:: For optimum experimental results, absorbance should be
measured at (or as close as possible to) lambda max of the solute
(the wavelength where absorbance is highest in the solute's
absorption spectrum). Answer: true
◉ EXPT1:: The colorimeter is always calibrated using pure water in
the cuvette. Answer: false
◉ EXPT1:: After you filter a cloudy (aspirin tablet + sodium
hydroxide) solution (that has been diluted to 250.00 mL), what do
,you need to save for use later in the experiment? Answer: filtrate
(liquid that passes through the filter)
◉ EXPT1:: Select the unitless quantities. Answer: - I/Io (ratio of
emergent to incident intensity)
- A (absorbance)
◉ EXPT1:: A transfer is quantitative, as done in Step 13 of Part B, if
Answer: you try to make sure every last molecule of acetylsalicylic
acid - sodium hydroxide solution is transferred to the 250 mL
volumetric flask
◉ EXPT1:: The concentration of a solution is an intensive property
of the solution. Answer: true
◉ EXPT1:: In this experiment, the absorbance, A, is directly
proportional to the solvent concentration, expressed in moles per
liter. Answer: false
◉ EXPT2:: Vigorous boiling of a liquid Answer: occurs throughout
the liquid
◉ EXPT2:: Evaporation from a volatile liquid occurs Answer: only
from the surface of the liquid
, ◉ EXPT2:: While a pure liquid is boiling, its temperature Answer:
remains constant
◉ EXPT2:: Consider a pure liquid at a temperature between its
melting and boiling points. The molecules which evaporate into the
gas phase are the ones traveling with _____ velocity. Answer: high
◉ EXPT2:: At a given temperature, all molecules of a pure gas have
identical molecular velocities. Answer: false
◉ EXPT2:: In this experiment, the liquid's heat of vaporization
Answer: is assumed constant if 10 <= T <= 40 (°C)
◉ EXPT2:: The vapor pressure of a pure liquid in a closed container
depends on Answer: - the temperature of the liquid
- the liquid
◉ EXPT2:: Select all parameters in the following list that change
while you are collecting data during the experiment Answer: - moles
of volatile liquid in the liquid phase in the sealed flask
- moles of volatile liquid in the gas phase in the sealed flask
- total pressure inside the flask
- pressure of air in the sealed flask
EXAM SCRIPT 2026 TEST PAPER QUESTIONS
AND SOLUTIONS GRADED A+
◉ EXPT1:: If you don't want to go the trouble of preparing solutions,
measuring absorbances, plotting a Beer's law graph, and calculating
molar absorptivity from the slope of the graph, the value of the
molar absorptivity, epsilon, can be looked up in the chemical
literature. Answer: false
◉ EXPT1:: When preparing an acid solution by dilution of the
concentrated acid, Answer: add water to the volumetric flask first,
then add the concentrated acid
◉ EXPT1:: For optimum experimental results, absorbance should be
measured at (or as close as possible to) lambda max of the solute
(the wavelength where absorbance is highest in the solute's
absorption spectrum). Answer: true
◉ EXPT1:: The colorimeter is always calibrated using pure water in
the cuvette. Answer: false
◉ EXPT1:: After you filter a cloudy (aspirin tablet + sodium
hydroxide) solution (that has been diluted to 250.00 mL), what do
,you need to save for use later in the experiment? Answer: filtrate
(liquid that passes through the filter)
◉ EXPT1:: Select the unitless quantities. Answer: - I/Io (ratio of
emergent to incident intensity)
- A (absorbance)
◉ EXPT1:: A transfer is quantitative, as done in Step 13 of Part B, if
Answer: you try to make sure every last molecule of acetylsalicylic
acid - sodium hydroxide solution is transferred to the 250 mL
volumetric flask
◉ EXPT1:: The concentration of a solution is an intensive property
of the solution. Answer: true
◉ EXPT1:: In this experiment, the absorbance, A, is directly
proportional to the solvent concentration, expressed in moles per
liter. Answer: false
◉ EXPT2:: Vigorous boiling of a liquid Answer: occurs throughout
the liquid
◉ EXPT2:: Evaporation from a volatile liquid occurs Answer: only
from the surface of the liquid
, ◉ EXPT2:: While a pure liquid is boiling, its temperature Answer:
remains constant
◉ EXPT2:: Consider a pure liquid at a temperature between its
melting and boiling points. The molecules which evaporate into the
gas phase are the ones traveling with _____ velocity. Answer: high
◉ EXPT2:: At a given temperature, all molecules of a pure gas have
identical molecular velocities. Answer: false
◉ EXPT2:: In this experiment, the liquid's heat of vaporization
Answer: is assumed constant if 10 <= T <= 40 (°C)
◉ EXPT2:: The vapor pressure of a pure liquid in a closed container
depends on Answer: - the temperature of the liquid
- the liquid
◉ EXPT2:: Select all parameters in the following list that change
while you are collecting data during the experiment Answer: - moles
of volatile liquid in the liquid phase in the sealed flask
- moles of volatile liquid in the gas phase in the sealed flask
- total pressure inside the flask
- pressure of air in the sealed flask
