CHEM 101L FINAL QUESTIONS AND ANSWERS
exit the lab and proceed to the stairs nearest the Venable parking lot and
Columbia Street. After exiting on the ground floor you should meet your TA on
the far side of the driveway to the parking lot so that you can be included in a
head count of those safely evacuated, keeping the drive clear for emergency
vehicles/exit the lab and proceed to the stairs nearest the elevator. After exiting
on the ground floor you should meet your TA in front of the sign for Kenan
Laboratories just off of South Road so that you can be included in a head count
of those safely evacuated.
In the event the fire alarm for Morehead Laboratory sounds, you must evacuate the
building. Assuming the emergency does not interfere with your best route, you
should__________ .
immediately dispose of the solid reagent into a solid waste container in the hood,
then dispose of the beaker in the glass waste container, and begin the experiment
again.
During lab, a beaker containing a solid reagent cracks. To be safe you should
____________
into the regular trash.
A Kim wipe that was used to polish the sides of a cute should be disposed of...
into the liquid waste container.
A small amount of sodium bicarbonate solution that was not used in the experiment
should be disposed of...
in a small bin just above the TA bench.
Green or silver lab gloves should be disposed of...
into the chemical solid waste container.
A paper towel that was used to wipe up a spilled solution should be disposed of...
proceed to the safety shower located just inside the door to the hallway, remove
both the lab coat and shirt, and rinse your skin for 15 minutes.
While carrying a vial of an organic liquid from the hood, it drops on the bench and
shatters, soaking the front of your lab coat and shirt. You should immediately
____________
20.35 mL
The volume marking at the sealed bottom of a buret segment is 38.60 mL, and has
markings for every 0.1 mL. When water is added, the bottom of the meniscus sits about
halfway between the line for 18.3 mL and the next mark up. What volume of water is
contained in the buret segment?
2
When calculating the displacement volume of the thermometer, the volume reading on
the buret is 29.37 mL without the thermometer, and 28.72 mL with the thermometer in
place. How many significant figures should be recorded for the displacement volume of
the thermometer?
-8.92 x 10-4 g mL-1 oC-1 represents the change in density as temperature
increases.
, Using the graph shown from an experiment measuring the density of water (y = -
0.0008918x + 1.0341956, R2 = 0.9767644), what would be the correct value, units, and
significance of the slope of the trendline?
The slope of the regression line would be correct, but the intercept would read a
value that was greater than the true value.
A student creates the following graph after an experiment measuring the density of
water (y = -0.0008918x + 1.0341956, R2 = 0.9767644). Suppose the thermometer the
student used was improperly calibrated and always read a value 1.5 degrees above the
true temperature. Which of the following statements would be true?
endothermic, because energy is transferred to the reaction from the
surroundings.
The temperature at the start of a reaction was 26.5°C and at the end of the reaction was
18.5°C. Based on these observations the reaction of sodium bicarbonate with citric acid
would be:
Cl-
The molecular equation for a reaction is: Mg (s) + 2 HCl (aq) →MgCl2 (aq) + H2 (g).
Both the initial HCl solution and the final solution were transparent and colorless, but
bubbles were seen during the reaction. Based on this equation and the observations of
the reaction, the spectator ions in the ionic equation would be:
endothermic
3.5 g of white crystalline solid is added to a calorimeter containing 30 mL of water at 22
°C. During the reaction, the solid crystals disappear and the temperature of the solution
decreases. Based on these observations the reaction would be classified as:
7.30
When viewed through a spectroscope, calcium ions produce three distinct lines in the
visible region of the spectrum, at spectroscope positions of 7.30, 7.85, and 8.45.
Assuming the linear fit for the calibration of the spectroscope has a positive slope, the
line corresponding to the highest energy would have a spectroscope position of:
The yellow color is characteristic of the changes in energy of an electron in the
Na+ metal ion.
Which of the following is a true statement about the bright yellow flame seen during a
flame test of a 1 M solution of NaCl in a Meker burner flame?
5
Given the Rydberg equation: ΔE = RH (1/(nf2)- 1/(ni2))
In the Balmer series for hydrogen, what is the initial energy level (ni) for a photon with a
wavelength of 434.1 nm? REMEMBER: h = 6.626 x 10-34 J⋅s; c = 2.998 x 108 m/s; RH
= 2.18 x 10-18 J
None of these is correct for a catalytic reaction.
According to the stoichiometry of the reaction equation 2 H2O2 (aq) → catalase → H2O
(l) + O2 (g), the maximum energy that can be released by this reaction would occur at a
H2O2:catalase ratio of
False
The following three actions could produce a significant source of error in the results for
Experiment 5:
Using an excess of yeast in the reaction with H2O2.
exit the lab and proceed to the stairs nearest the Venable parking lot and
Columbia Street. After exiting on the ground floor you should meet your TA on
the far side of the driveway to the parking lot so that you can be included in a
head count of those safely evacuated, keeping the drive clear for emergency
vehicles/exit the lab and proceed to the stairs nearest the elevator. After exiting
on the ground floor you should meet your TA in front of the sign for Kenan
Laboratories just off of South Road so that you can be included in a head count
of those safely evacuated.
In the event the fire alarm for Morehead Laboratory sounds, you must evacuate the
building. Assuming the emergency does not interfere with your best route, you
should__________ .
immediately dispose of the solid reagent into a solid waste container in the hood,
then dispose of the beaker in the glass waste container, and begin the experiment
again.
During lab, a beaker containing a solid reagent cracks. To be safe you should
____________
into the regular trash.
A Kim wipe that was used to polish the sides of a cute should be disposed of...
into the liquid waste container.
A small amount of sodium bicarbonate solution that was not used in the experiment
should be disposed of...
in a small bin just above the TA bench.
Green or silver lab gloves should be disposed of...
into the chemical solid waste container.
A paper towel that was used to wipe up a spilled solution should be disposed of...
proceed to the safety shower located just inside the door to the hallway, remove
both the lab coat and shirt, and rinse your skin for 15 minutes.
While carrying a vial of an organic liquid from the hood, it drops on the bench and
shatters, soaking the front of your lab coat and shirt. You should immediately
____________
20.35 mL
The volume marking at the sealed bottom of a buret segment is 38.60 mL, and has
markings for every 0.1 mL. When water is added, the bottom of the meniscus sits about
halfway between the line for 18.3 mL and the next mark up. What volume of water is
contained in the buret segment?
2
When calculating the displacement volume of the thermometer, the volume reading on
the buret is 29.37 mL without the thermometer, and 28.72 mL with the thermometer in
place. How many significant figures should be recorded for the displacement volume of
the thermometer?
-8.92 x 10-4 g mL-1 oC-1 represents the change in density as temperature
increases.
, Using the graph shown from an experiment measuring the density of water (y = -
0.0008918x + 1.0341956, R2 = 0.9767644), what would be the correct value, units, and
significance of the slope of the trendline?
The slope of the regression line would be correct, but the intercept would read a
value that was greater than the true value.
A student creates the following graph after an experiment measuring the density of
water (y = -0.0008918x + 1.0341956, R2 = 0.9767644). Suppose the thermometer the
student used was improperly calibrated and always read a value 1.5 degrees above the
true temperature. Which of the following statements would be true?
endothermic, because energy is transferred to the reaction from the
surroundings.
The temperature at the start of a reaction was 26.5°C and at the end of the reaction was
18.5°C. Based on these observations the reaction of sodium bicarbonate with citric acid
would be:
Cl-
The molecular equation for a reaction is: Mg (s) + 2 HCl (aq) →MgCl2 (aq) + H2 (g).
Both the initial HCl solution and the final solution were transparent and colorless, but
bubbles were seen during the reaction. Based on this equation and the observations of
the reaction, the spectator ions in the ionic equation would be:
endothermic
3.5 g of white crystalline solid is added to a calorimeter containing 30 mL of water at 22
°C. During the reaction, the solid crystals disappear and the temperature of the solution
decreases. Based on these observations the reaction would be classified as:
7.30
When viewed through a spectroscope, calcium ions produce three distinct lines in the
visible region of the spectrum, at spectroscope positions of 7.30, 7.85, and 8.45.
Assuming the linear fit for the calibration of the spectroscope has a positive slope, the
line corresponding to the highest energy would have a spectroscope position of:
The yellow color is characteristic of the changes in energy of an electron in the
Na+ metal ion.
Which of the following is a true statement about the bright yellow flame seen during a
flame test of a 1 M solution of NaCl in a Meker burner flame?
5
Given the Rydberg equation: ΔE = RH (1/(nf2)- 1/(ni2))
In the Balmer series for hydrogen, what is the initial energy level (ni) for a photon with a
wavelength of 434.1 nm? REMEMBER: h = 6.626 x 10-34 J⋅s; c = 2.998 x 108 m/s; RH
= 2.18 x 10-18 J
None of these is correct for a catalytic reaction.
According to the stoichiometry of the reaction equation 2 H2O2 (aq) → catalase → H2O
(l) + O2 (g), the maximum energy that can be released by this reaction would occur at a
H2O2:catalase ratio of
False
The following three actions could produce a significant source of error in the results for
Experiment 5:
Using an excess of yeast in the reaction with H2O2.
