CHEM 101L QUESTIONS AND ANSWERS
The volume marking at the bottom of a buret segment is 28.00 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 22.2 mL and the next mark up. What volume of
water is contained in the buret segment?
A. 22.2 mL
B. 22.25 mL
C. 5.75 mL
D. 5.85 mL
D.
A student creates the following graph after an experiment measuring the density
of water. In that experiment, the mass was measured to the third decimal place,
the ~8 mL volume to the second decimal place, and the temperature to the first
decimal place. Based on this information, how should the student label the axes?
A. y-axis: density (mL/degrees C) with 3 significant figures x-axis: mass (g) with
four significant figures.
B. y-axis: temperature (degrees C) with 3 significant figures x-axis: density (g/mL)
with four significant figures.
C. y-axis: density (g/mL) with 3 significant figures
x-axis: temperature (degrees C) with 3 significant figures
D. y-axis: density (g/degrees C) with 4 significant figures x-axis: temperature
(degrees C) with 1 significant figure.
C
Using the same graph from the previous question, created in the same
experiment, what would be the correct value, units, and significance of the slope
of the trendline?
A. -8.918 x 10-4 g mL-1 oC-1 represents the change in volume as temperature
increases.
B.-8.92 x 10-4 g mL-1 oC-1 represents the change in density as temperature
increases.
C. 1.034 g mL-1 oC-1 represents the change in volume as temperature increases.
Incorrect
D.1.03 g/mL represents the density at a temperature of 0oC.
B
Two students carry out the same experiment, but the densities calculated by the
first student are always 0.05 g/mL larger than those calculated by the second
student for the same temperatures. The sources of error for the first student
would be characterized as ________________, which would mostly affect the
________________ of the reported results.
A. random; accuracy
B. systematic; accuracy
C. random; precision
D. systematic; precision
, B
Your lab partner gets a chemical in his eye during lab, and is in great pain,
needing help to get to the eyewash. It is your responsibility to get him to the
eyewash which is located ____________________ and to help hold his eyes open
in the eyewash for 15 minutes
A. just inside the door to the hallway
B. in the sink at the front of the lab, next to the white board
C. inside the fume hood
D.in the sinks in each lab bench
B
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
A. 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.
B. remove the lab coat and ask your TA if the chemical is hazardous.
C. proceed to the rest room on the same floor as your lab room where you can
remove the lab coat and rinse the chemical from your shirt.
D. proceed to the safety shower located just outside the door to the hallway,
remove both the lab coat and shirt, and rinse your skin for 15 minutes.
A
For the reaction of 3.5 g of barium hydroxide, Ba(OH)2 with excess ammonium
chloride, the temperature decreases from 22.4°C to 12.7°C. The value of ΔT/mol
(°C/mol) would be:
A. -2.77 °C/mol
B. c.- 0.00210 °C/mol
C. -0.361 °C/mol
D. -475 °C/mol
E. None of the answers is correct.
D
3.5 g of barium hydroxide is added to a calorimeter containing 30 mL of 0.5 M
ammonium chloride at 22 °C. During the reaction, the solution bubbles
continuously and remains milky white. Based on these observations the reaction
would be classified as:
A. acid-base
B. precipitation
C. none of the above
D. gas-forming
E. dissolution
F. complexation
A, B, D, E
A technique in which the temperature change in a closed system is measured to
assess the heat transfer between a reaction and its surroundings is called
A. Precipitation
B. Dissolution
C. Calorimetry
D. Complexation
The volume marking at the bottom of a buret segment is 28.00 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 22.2 mL and the next mark up. What volume of
water is contained in the buret segment?
A. 22.2 mL
B. 22.25 mL
C. 5.75 mL
D. 5.85 mL
D.
A student creates the following graph after an experiment measuring the density
of water. In that experiment, the mass was measured to the third decimal place,
the ~8 mL volume to the second decimal place, and the temperature to the first
decimal place. Based on this information, how should the student label the axes?
A. y-axis: density (mL/degrees C) with 3 significant figures x-axis: mass (g) with
four significant figures.
B. y-axis: temperature (degrees C) with 3 significant figures x-axis: density (g/mL)
with four significant figures.
C. y-axis: density (g/mL) with 3 significant figures
x-axis: temperature (degrees C) with 3 significant figures
D. y-axis: density (g/degrees C) with 4 significant figures x-axis: temperature
(degrees C) with 1 significant figure.
C
Using the same graph from the previous question, created in the same
experiment, what would be the correct value, units, and significance of the slope
of the trendline?
A. -8.918 x 10-4 g mL-1 oC-1 represents the change in volume as temperature
increases.
B.-8.92 x 10-4 g mL-1 oC-1 represents the change in density as temperature
increases.
C. 1.034 g mL-1 oC-1 represents the change in volume as temperature increases.
Incorrect
D.1.03 g/mL represents the density at a temperature of 0oC.
B
Two students carry out the same experiment, but the densities calculated by the
first student are always 0.05 g/mL larger than those calculated by the second
student for the same temperatures. The sources of error for the first student
would be characterized as ________________, which would mostly affect the
________________ of the reported results.
A. random; accuracy
B. systematic; accuracy
C. random; precision
D. systematic; precision
, B
Your lab partner gets a chemical in his eye during lab, and is in great pain,
needing help to get to the eyewash. It is your responsibility to get him to the
eyewash which is located ____________________ and to help hold his eyes open
in the eyewash for 15 minutes
A. just inside the door to the hallway
B. in the sink at the front of the lab, next to the white board
C. inside the fume hood
D.in the sinks in each lab bench
B
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
A. 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.
B. remove the lab coat and ask your TA if the chemical is hazardous.
C. proceed to the rest room on the same floor as your lab room where you can
remove the lab coat and rinse the chemical from your shirt.
D. proceed to the safety shower located just outside the door to the hallway,
remove both the lab coat and shirt, and rinse your skin for 15 minutes.
A
For the reaction of 3.5 g of barium hydroxide, Ba(OH)2 with excess ammonium
chloride, the temperature decreases from 22.4°C to 12.7°C. The value of ΔT/mol
(°C/mol) would be:
A. -2.77 °C/mol
B. c.- 0.00210 °C/mol
C. -0.361 °C/mol
D. -475 °C/mol
E. None of the answers is correct.
D
3.5 g of barium hydroxide is added to a calorimeter containing 30 mL of 0.5 M
ammonium chloride at 22 °C. During the reaction, the solution bubbles
continuously and remains milky white. Based on these observations the reaction
would be classified as:
A. acid-base
B. precipitation
C. none of the above
D. gas-forming
E. dissolution
F. complexation
A, B, D, E
A technique in which the temperature change in a closed system is measured to
assess the heat transfer between a reaction and its surroundings is called
A. Precipitation
B. Dissolution
C. Calorimetry
D. Complexation
