CHEM 121 LAB REPORTS 3 CERTIFICATION
EVALUATION TEST PAPER 2026 COMPLETE
STUDY QUESTIONS WITH CORRECT ANSWERS
◉ When using a properly stabilized balance, how should you ensure
that you get the most accurate mass reading possible? Answer:
Measure the mass of the sample at room temp. Close the side shields
on the balance during reading.
◉ Identify effective techniques for accurate pipet use. Answer: Do
not let liquid enter the pipet bulb or pump. Measure liquid by
aligning meniscus with the volume line.
◉ In order to use a pipet, place a _____ at the top of the pipet. Use this
object to fill the pipet such that the
______ of the liquid is even with the volume line. Release the liquid,
touching the tip of the pipet to the side of the container if necessary
to release the last drop _____ the pipet tip. Answer: blub or pump,
meniscus, outside the pipet
◉ A 24.5 g sample of solution has a density of 0.768 g/mL. What is
the sample volume (in mL)? Answer: 31.9 mL
24.5g/0.768 g/mL=
,◉ Average mass calculations Answer: add all data up and divide by
the number of trials
◉ Suppose that two students perform a titration experiment
multiple times, resulting in the average concentrations reported
here.
Student A : 0.125+/- 0.008M
Student B: 0.12+/- 0.03 M
The more precise work was done by_____ because_____ Answer:
Student A, the students data has a smaller standard deviation
◉ How many sig figs in the number 5.0002? Answer: 5
◉ When you are done using most glassware in the lab, what should
you do? Answer: Return the glassware to the appropriate location to
dry. Clean the glassware with a detergent solution. Dispose of any
chemicals in the proper waste container.
◉ What purpose can funnels serve in the lab? Answer: Support for
filter paper during gravity filtration. Assistance of pouring liquids in
burets. Help for transferring solid chemicals from weigh boats.
, ◉ Identify techniques to be used for accurate solution preparation
using a volumetric flask. Answer: After the solvent is added, stopper
and invert the flask to mix the solution. Read the liquid volume at
eye level from the bottom of the meniscus
◉ After a mixture has been poured through filter paper, the
________ component remains on top while the
___________ flows through. To collect the solid, spread the filter paper
___________and allow the solvent to
________ Answer: solid, liquid, on a watch glass, evaporate
◉ When heating liquids in a test tube, it is important that the test
tube be positioned ______, pointed
______ people, and
_________ Answer: at an angle, away from, half-full
◉ A pill that is 91.5% aspirin is found to contain 58.41 mg of aspirin.
What is the mass of the pill in milligrams? Answer: 63.8 mg
◉ Suppose a student starts with 2.3524 g of a sand mixture and
separates the components into 1.3012 g of
NaCl
, 0.5774 g of
EVALUATION TEST PAPER 2026 COMPLETE
STUDY QUESTIONS WITH CORRECT ANSWERS
◉ When using a properly stabilized balance, how should you ensure
that you get the most accurate mass reading possible? Answer:
Measure the mass of the sample at room temp. Close the side shields
on the balance during reading.
◉ Identify effective techniques for accurate pipet use. Answer: Do
not let liquid enter the pipet bulb or pump. Measure liquid by
aligning meniscus with the volume line.
◉ In order to use a pipet, place a _____ at the top of the pipet. Use this
object to fill the pipet such that the
______ of the liquid is even with the volume line. Release the liquid,
touching the tip of the pipet to the side of the container if necessary
to release the last drop _____ the pipet tip. Answer: blub or pump,
meniscus, outside the pipet
◉ A 24.5 g sample of solution has a density of 0.768 g/mL. What is
the sample volume (in mL)? Answer: 31.9 mL
24.5g/0.768 g/mL=
,◉ Average mass calculations Answer: add all data up and divide by
the number of trials
◉ Suppose that two students perform a titration experiment
multiple times, resulting in the average concentrations reported
here.
Student A : 0.125+/- 0.008M
Student B: 0.12+/- 0.03 M
The more precise work was done by_____ because_____ Answer:
Student A, the students data has a smaller standard deviation
◉ How many sig figs in the number 5.0002? Answer: 5
◉ When you are done using most glassware in the lab, what should
you do? Answer: Return the glassware to the appropriate location to
dry. Clean the glassware with a detergent solution. Dispose of any
chemicals in the proper waste container.
◉ What purpose can funnels serve in the lab? Answer: Support for
filter paper during gravity filtration. Assistance of pouring liquids in
burets. Help for transferring solid chemicals from weigh boats.
, ◉ Identify techniques to be used for accurate solution preparation
using a volumetric flask. Answer: After the solvent is added, stopper
and invert the flask to mix the solution. Read the liquid volume at
eye level from the bottom of the meniscus
◉ After a mixture has been poured through filter paper, the
________ component remains on top while the
___________ flows through. To collect the solid, spread the filter paper
___________and allow the solvent to
________ Answer: solid, liquid, on a watch glass, evaporate
◉ When heating liquids in a test tube, it is important that the test
tube be positioned ______, pointed
______ people, and
_________ Answer: at an angle, away from, half-full
◉ A pill that is 91.5% aspirin is found to contain 58.41 mg of aspirin.
What is the mass of the pill in milligrams? Answer: 63.8 mg
◉ Suppose a student starts with 2.3524 g of a sand mixture and
separates the components into 1.3012 g of
NaCl
, 0.5774 g of
