CHEM 120LEXAM WITH CORRECT
QUESTIONS AND ANSWERS 2025
A. Goggles must be worn because: - CORRECT-ANSWERS--User inexperience increases
the chance of splashes and chemical spills
B. --The number of students working in the lab increases the chances of collision and
subsequently chemical splashes
C. --They provide protection from flying objects such as broken shards of glass
D. --They provide maximum protection from chemicals spilled or splashed in the eyes
E. To maintain a safe working environment in the laboratory it is important for each student
to: - CORRECT-ANSWERSBecome familiar with the safe handling procedures for each
chemical used
F. Clean up all spills as soon as they occur
G. Learn the location of all safety equipment in the lab room
H. Keep aisles between benches free of trip hazards such as knapsacks or unused stools
I. Liquid dripping down the sides of a bottles poses a safety hazard because: - CORRECT-
ANSWERSIt leaves "bottle ring" spills which could damage or react with the bench
surface
J. It makes the bottle slippery and increases the chances of dropping it
, K. It could be dangerous for the next user to touch
L. Fire safety in the First Year Chemistry lab requires that each student learn the location of:
- CORRECT-ANSWERSThe nearest fire alarm pull station
M. The nearest fire extinguisher
N. The fire exit route from the room and building
O. Which of the following precautions should be taken to ensure that all of the initial copper
is recovered? - CORRECT-ANSWERSAvoid spilling solutions during transfer
P. Stir continuously when boiling to avoid bumping
Q. Solid products adhering to beakers should be added into the next solution
R. When using vacuum filtration to separate a solid product from a liquid, what is the
maximum depth of solution that should be added to the Buchner funnel? - CORRECT-
ANSWERStwo-thirds of the depth of the funnel
S. In the technique of vacuum filtration, what is the "filtrate"? - CORRECT-ANSWERSthe
liquid that is drawn into the flask
T. what is bumping? - CORRECT-ANSWERSThe formation and subsequent bursting of
large air bubbles trapped under a layer of solid precipitate in solution
U. What does it mean to "decant the solution"? - CORRECT-ANSWERSto pour off a liquid
to separate it from a solid precipitate
V. What does it mean to "quantitatively transfer"? - CORRECT-ANSWERSTo move all
material from one location to another with no loss of material
W. What is a supernatant? - CORRECT-ANSWERSThe liquid overlying a precipitated solid
QUESTIONS AND ANSWERS 2025
A. Goggles must be worn because: - CORRECT-ANSWERS--User inexperience increases
the chance of splashes and chemical spills
B. --The number of students working in the lab increases the chances of collision and
subsequently chemical splashes
C. --They provide protection from flying objects such as broken shards of glass
D. --They provide maximum protection from chemicals spilled or splashed in the eyes
E. To maintain a safe working environment in the laboratory it is important for each student
to: - CORRECT-ANSWERSBecome familiar with the safe handling procedures for each
chemical used
F. Clean up all spills as soon as they occur
G. Learn the location of all safety equipment in the lab room
H. Keep aisles between benches free of trip hazards such as knapsacks or unused stools
I. Liquid dripping down the sides of a bottles poses a safety hazard because: - CORRECT-
ANSWERSIt leaves "bottle ring" spills which could damage or react with the bench
surface
J. It makes the bottle slippery and increases the chances of dropping it
, K. It could be dangerous for the next user to touch
L. Fire safety in the First Year Chemistry lab requires that each student learn the location of:
- CORRECT-ANSWERSThe nearest fire alarm pull station
M. The nearest fire extinguisher
N. The fire exit route from the room and building
O. Which of the following precautions should be taken to ensure that all of the initial copper
is recovered? - CORRECT-ANSWERSAvoid spilling solutions during transfer
P. Stir continuously when boiling to avoid bumping
Q. Solid products adhering to beakers should be added into the next solution
R. When using vacuum filtration to separate a solid product from a liquid, what is the
maximum depth of solution that should be added to the Buchner funnel? - CORRECT-
ANSWERStwo-thirds of the depth of the funnel
S. In the technique of vacuum filtration, what is the "filtrate"? - CORRECT-ANSWERSthe
liquid that is drawn into the flask
T. what is bumping? - CORRECT-ANSWERSThe formation and subsequent bursting of
large air bubbles trapped under a layer of solid precipitate in solution
U. What does it mean to "decant the solution"? - CORRECT-ANSWERSto pour off a liquid
to separate it from a solid precipitate
V. What does it mean to "quantitatively transfer"? - CORRECT-ANSWERSTo move all
material from one location to another with no loss of material
W. What is a supernatant? - CORRECT-ANSWERSThe liquid overlying a precipitated solid
