CHEM 162 EXPERIMENT 2 COMPLETE STUDY
GUIDE WITH SOLVED QUESTIONS
◉ When should you not wear gloves in the laboratory setting?
(select all that apply)
a. When weighing out reagents at the balances
b. When entering data into your ELN on your laptop
c. When adding a Kimwipe to the solid waste container
d. When handling clean glassware
e. When opening the door to go to the restroom
f. When writing notes on scratch paper using a pen and paper
g. When adding chemicals to the liquid waste
Answer: b, e, f
◉ You are adding 0.1 M NaOH to a cuvette containing crystal violet.
While using the micropipette, you spill 100µL onto your bare arm.
What should you do?
Answer: wash off w/ water, tell TA
,◉ Iron Man is taking an evening laboratory session and wants to
bring a snack to help him make to through the evening. When should
he be allowed to have food at the bench top in the lab?
a. If the experiment work is over and cleaned up
b. At the beginning because it is dinner time and crime fighting is
exhausting
c. Only if the food remains in the students backpack while at the
bench top
d. Never
e. Iron Man is hypoglycemic and should be allowed to eat at the
bench to prevent health issues
Answer: d
◉ ______ error arises from a flaw in the equipment or in the
experimental design. This type of error ____ be detected and
corrected. Provide several examples.
Answer: systematic, can
sig figs, old equipment, incorrect calibration
◉ ______ error arises from uncontrolled, and often times
uncontrollable, variables in an experiment which has equal chance
of being positive and negative. This type of error ____ be detected and
corrected. Provide several examples.
, Answer: random, can't
inaccurate reading of buret (miniscus), equipment noise
(movement)
◉ Define accuracy
Answer: how close a measurement is to the true value
◉ What does systematic error affect more: accuracy or precision?
How does one minimize the influence of systematic error in one's
results?
Answer: accuracy
- calibrate correctly
- read/use equipment correctly
◉ Define precision
Answer: how close the measured values are to each other
◉ What does random error effect more: accuracy or precision? How
does one minimize the influence of random error in one's results?
Answer: precision
- use more modern equipment
◉ Accuracy or precision?
GUIDE WITH SOLVED QUESTIONS
◉ When should you not wear gloves in the laboratory setting?
(select all that apply)
a. When weighing out reagents at the balances
b. When entering data into your ELN on your laptop
c. When adding a Kimwipe to the solid waste container
d. When handling clean glassware
e. When opening the door to go to the restroom
f. When writing notes on scratch paper using a pen and paper
g. When adding chemicals to the liquid waste
Answer: b, e, f
◉ You are adding 0.1 M NaOH to a cuvette containing crystal violet.
While using the micropipette, you spill 100µL onto your bare arm.
What should you do?
Answer: wash off w/ water, tell TA
,◉ Iron Man is taking an evening laboratory session and wants to
bring a snack to help him make to through the evening. When should
he be allowed to have food at the bench top in the lab?
a. If the experiment work is over and cleaned up
b. At the beginning because it is dinner time and crime fighting is
exhausting
c. Only if the food remains in the students backpack while at the
bench top
d. Never
e. Iron Man is hypoglycemic and should be allowed to eat at the
bench to prevent health issues
Answer: d
◉ ______ error arises from a flaw in the equipment or in the
experimental design. This type of error ____ be detected and
corrected. Provide several examples.
Answer: systematic, can
sig figs, old equipment, incorrect calibration
◉ ______ error arises from uncontrolled, and often times
uncontrollable, variables in an experiment which has equal chance
of being positive and negative. This type of error ____ be detected and
corrected. Provide several examples.
, Answer: random, can't
inaccurate reading of buret (miniscus), equipment noise
(movement)
◉ Define accuracy
Answer: how close a measurement is to the true value
◉ What does systematic error affect more: accuracy or precision?
How does one minimize the influence of systematic error in one's
results?
Answer: accuracy
- calibrate correctly
- read/use equipment correctly
◉ Define precision
Answer: how close the measured values are to each other
◉ What does random error effect more: accuracy or precision? How
does one minimize the influence of random error in one's results?
Answer: precision
- use more modern equipment
◉ Accuracy or precision?
