CHEM 103 Lab Exam 1 Solutions
When making observations, what are the things you should describe? - ANS-smell,
appearance, and state of matter of chemicals before and after the reaction, how long
the reaction occurred, and names of chemicals
What is the density of a substance? - ANS-The amount of matter contained in a specific
sized sample of that substance; mass per unit of volume
Will the density of a given substance always be the same despite the volume (as long
as the are under the same specific set of conditions)? - ANS-yes
Equation for density - ANS-mass divided by volume (g/mL)
1 mL is equal to how many cubic cm? - ANS-1
Density of pure water - ANS-1.00 g/mL
Equation for volume - ANS-length x width x height
What is the displacement method? - ANS-the volume of an irregularly shaped object
can be measured indirectly by observing the amount of liquid it displaces in a graduated
cylinder.
What is decantation? - ANS-a process of separating a solid residue (precipitate) from a
liquid (the supernate) by gently pouring off the liquid without disturbing the solid that has
settled to the bottom
What is filtration? - ANS-a process of separating a solid from a liquid by using a filter
through which the liquid, but not the solid, can pass. To speed up the process, suction
can be used make it faster by placing a filter in the bottom of a Buchner funnel (vacuum
filtration).
What is a piece of glassware designed to accurately measure volumes of liquids? -
ANS-graduated cylinder
What is the curved surface of a graduated cylinder? - ANS-meniscus
When making observations, what are the things you should describe? - ANS-smell,
appearance, and state of matter of chemicals before and after the reaction, how long
the reaction occurred, and names of chemicals
What is the density of a substance? - ANS-The amount of matter contained in a specific
sized sample of that substance; mass per unit of volume
Will the density of a given substance always be the same despite the volume (as long
as the are under the same specific set of conditions)? - ANS-yes
Equation for density - ANS-mass divided by volume (g/mL)
1 mL is equal to how many cubic cm? - ANS-1
Density of pure water - ANS-1.00 g/mL
Equation for volume - ANS-length x width x height
What is the displacement method? - ANS-the volume of an irregularly shaped object
can be measured indirectly by observing the amount of liquid it displaces in a graduated
cylinder.
What is decantation? - ANS-a process of separating a solid residue (precipitate) from a
liquid (the supernate) by gently pouring off the liquid without disturbing the solid that has
settled to the bottom
What is filtration? - ANS-a process of separating a solid from a liquid by using a filter
through which the liquid, but not the solid, can pass. To speed up the process, suction
can be used make it faster by placing a filter in the bottom of a Buchner funnel (vacuum
filtration).
What is a piece of glassware designed to accurately measure volumes of liquids? -
ANS-graduated cylinder
What is the curved surface of a graduated cylinder? - ANS-meniscus
