CHM 113 LAB FINAL QUESTIONS &
ANSWERS CORRECT 100%
In most experiments, what is the least number of measurements (trials) when you
are making quantitative measurements in lab?
1
2
3 - ANSWER3
If a student determined that the volume of a sample of water is 11.4 mL, and its
mass is 10.98 g, what should the student record as the experimental density of the
water sample, with the correct number of significant figures?
1.038g/mL
1.04g/mL
0.963g/mL
0.96g/mL
125g/mL - ANSWER0.963g/mL
A student determines the mass of a sample of water by determining the mass of an
empty container (99.20 g) and the mass of the container including the sample of
water (108.23 g). Use significant rules (for subtracting) to determine the mass of the
water sample alone, to the correct number of significant figures.
9g
9.0g
9.03g
9.030g
9.0300g - ANSWER9.03g
True or False. A hot plate is used for heating the hydrate in a crucible at least 2
times for 10-15 minutes at medium-high setting.
True
False - ANSWERTrue
What is the molar mass of nickel(II) chloride hexahydrate, NiCl2•6H2O?
237.69 g/mol
129.60 g/mol
21411.12 g/mol
147.62 g/mol
108.10 g/mol - ANSWER237.69 g/mol
How can you make sure that all of the water of hydration is removed?
Heat the sample 5 minutes longer than the lab recommends.
, Perform a heating, cooling, weighing cycle until duplicate masses are obtained
between weighing cycles.
Touch the powder with your finger to see if it feels wet.
It is dry when it changes color.
When the sample turns black and starts smoking, it is done. - ANSWERPerform a
heating, cooling, weighing cycle until duplicate masses are obtained between
weighing cycles.
What does anhydrous mean?
without water
without hydrogen
absorber of water
absorber of hydrogen - ANSWERwithout water
An everyday example of a hydrate is
brownies
moss
flour
concrete
sawdust - ANSWERconcrete
What is the molar mass of anhydrous nickel(II) chloride hexahydrate, NiCl2•6H2O?
237.69 g/mol
129.60 g/mol
21411.12 g/mol
147.62 g/mol
108.10 g/mol - ANSWER129.60 g/mol
Upon heating a sample of NiCl2•6H2O, a sample originally weighing 3.5 g yields an
anhydrous salt residue weighing 2.1g. How many moles of water were in the
sample?
237.69 mol H2O
0.194 mol H2O
0.117 mol H2O
0.0777 mol H2O
18.02 mol H2O - ANSWER0.0777 mol H2O
Upon heating a sample of NiCl2•6H2O, a sample originally weighing 3.5 g yields an
anhydrous salt residue weighing 2.1g. What is the percent by mass of water in the
hydrate?
ANSWERS CORRECT 100%
In most experiments, what is the least number of measurements (trials) when you
are making quantitative measurements in lab?
1
2
3 - ANSWER3
If a student determined that the volume of a sample of water is 11.4 mL, and its
mass is 10.98 g, what should the student record as the experimental density of the
water sample, with the correct number of significant figures?
1.038g/mL
1.04g/mL
0.963g/mL
0.96g/mL
125g/mL - ANSWER0.963g/mL
A student determines the mass of a sample of water by determining the mass of an
empty container (99.20 g) and the mass of the container including the sample of
water (108.23 g). Use significant rules (for subtracting) to determine the mass of the
water sample alone, to the correct number of significant figures.
9g
9.0g
9.03g
9.030g
9.0300g - ANSWER9.03g
True or False. A hot plate is used for heating the hydrate in a crucible at least 2
times for 10-15 minutes at medium-high setting.
True
False - ANSWERTrue
What is the molar mass of nickel(II) chloride hexahydrate, NiCl2•6H2O?
237.69 g/mol
129.60 g/mol
21411.12 g/mol
147.62 g/mol
108.10 g/mol - ANSWER237.69 g/mol
How can you make sure that all of the water of hydration is removed?
Heat the sample 5 minutes longer than the lab recommends.
, Perform a heating, cooling, weighing cycle until duplicate masses are obtained
between weighing cycles.
Touch the powder with your finger to see if it feels wet.
It is dry when it changes color.
When the sample turns black and starts smoking, it is done. - ANSWERPerform a
heating, cooling, weighing cycle until duplicate masses are obtained between
weighing cycles.
What does anhydrous mean?
without water
without hydrogen
absorber of water
absorber of hydrogen - ANSWERwithout water
An everyday example of a hydrate is
brownies
moss
flour
concrete
sawdust - ANSWERconcrete
What is the molar mass of anhydrous nickel(II) chloride hexahydrate, NiCl2•6H2O?
237.69 g/mol
129.60 g/mol
21411.12 g/mol
147.62 g/mol
108.10 g/mol - ANSWER129.60 g/mol
Upon heating a sample of NiCl2•6H2O, a sample originally weighing 3.5 g yields an
anhydrous salt residue weighing 2.1g. How many moles of water were in the
sample?
237.69 mol H2O
0.194 mol H2O
0.117 mol H2O
0.0777 mol H2O
18.02 mol H2O - ANSWER0.0777 mol H2O
Upon heating a sample of NiCl2•6H2O, a sample originally weighing 3.5 g yields an
anhydrous salt residue weighing 2.1g. What is the percent by mass of water in the
hydrate?
