CHM 113 FINAL EXAM QUESTIONS & ANSWERS
Why is eye protection required in the lab? - Answer -to protect your eyes from harmful
chemicals
What is the policy on doing unauthorized experiments in the lab? - Answer -it is not
allowed
What is the laboratory dress code? - Answer -closed-toe shoes, long pants and
appropriate shirt
What is the policy regarding food and beverages in the lab? - Answer -must be
discarded before entering lab
What chemical compound is in the hoods and is used as a sweeping compound for all
spills? - Answer -sodium bicarbonate / kitty litter
What should be done if you get acid or base on you? - Answer -go to the shower and
remove all clothing
Should a hotplate always be operated at the highest position? What is the max setting?
- Answer -no; 3
Describe and sketch the plot of Temperature vs. Time for the evaporation of alcohol.
Why does the plot appear as it does? (explain any increases/decreases in
temperature)? - Answer -- when you stick the probe in the alcohol, the temperature is
going to be at its highest point
- when the probe is removed, the temperature will immediately decrease and then
increase again until it has reached room temp
- then it will flatten and remain flat
Describe and sketch the plot of Temperature vs. Time for the freezing point of Lauric
Acid. Why does the plot appear as it does (there should be 3 important "sections" in the
plot, explain what is happening in each)? - Answer -- in the first part of the graph, or
increase in temp, the probe is introduced to the hot temp of Lauric Acid in its liquid state
-- even though it has been introduced to cold water
- in the middle of the graph, the melting point is identified as the flat line. this is because
the lauric acid has once again solidified
- soon though, the lauric acid temp begins to decrease to its freezing point
DENSITY - Answer -...
Density - Answer -mass divided by volume (d = m /v)
Specific Gravity - Answer -the ratio of the density of a substance to the density of water
, Intensive Property - Answer -properties independent of mass (ex: density, specific heat,
equivalent weight)
Extensive Property - Answer -properties dependent of mass (ex: volume and mass)
For a piece of wood having:
Length = 10.35 cm
Width = 6.42 cm
Height = 1.90 cm
Mass = 74.212 g
Calculate the density - Answer -d = m / (lxwxh) = (74.212 g) / (10.35)*(6.42)*(1.90) =
0.587 g/cm^3
What are the units of density? - Answer -g/mL and g/cm^3
What are the units of specific gravity? - Answer -it is unitless
You must bring your lab manual to every lab session - Answer -True
Safety glasses can be removed once you are entering data in your lab notebook -
Answer -False
You must wear full coverage shoes at all time in lab - Answer -True
You are allowed to pipet out liquids by mouth - Answer -False
You should use glass containers, such as beakers, to collect ice out of an ice machine -
Answer -False
Liquid organic waste can go down the drain - Answer -False
At what temperature is water most dense? what is its physical state at that temperature
and the numeric value for its density? - Answer -4 degrees celsius, liquid, 1 g/mL
What is the volume occupied by 10 g of Iron? DFe = 7.87 g/cm^3 - Answer -d = 10 g /
v; d = 7.87 g/cm^3 = 1.27 cm^3
Intensive (I) or Extensive (E) property?
1. Temperature
2. Mass
3. Density
4. Color
5. Boiling Point - Answer -1. = I
2. = E
3. = I
4. = I
Why is eye protection required in the lab? - Answer -to protect your eyes from harmful
chemicals
What is the policy on doing unauthorized experiments in the lab? - Answer -it is not
allowed
What is the laboratory dress code? - Answer -closed-toe shoes, long pants and
appropriate shirt
What is the policy regarding food and beverages in the lab? - Answer -must be
discarded before entering lab
What chemical compound is in the hoods and is used as a sweeping compound for all
spills? - Answer -sodium bicarbonate / kitty litter
What should be done if you get acid or base on you? - Answer -go to the shower and
remove all clothing
Should a hotplate always be operated at the highest position? What is the max setting?
- Answer -no; 3
Describe and sketch the plot of Temperature vs. Time for the evaporation of alcohol.
Why does the plot appear as it does? (explain any increases/decreases in
temperature)? - Answer -- when you stick the probe in the alcohol, the temperature is
going to be at its highest point
- when the probe is removed, the temperature will immediately decrease and then
increase again until it has reached room temp
- then it will flatten and remain flat
Describe and sketch the plot of Temperature vs. Time for the freezing point of Lauric
Acid. Why does the plot appear as it does (there should be 3 important "sections" in the
plot, explain what is happening in each)? - Answer -- in the first part of the graph, or
increase in temp, the probe is introduced to the hot temp of Lauric Acid in its liquid state
-- even though it has been introduced to cold water
- in the middle of the graph, the melting point is identified as the flat line. this is because
the lauric acid has once again solidified
- soon though, the lauric acid temp begins to decrease to its freezing point
DENSITY - Answer -...
Density - Answer -mass divided by volume (d = m /v)
Specific Gravity - Answer -the ratio of the density of a substance to the density of water
, Intensive Property - Answer -properties independent of mass (ex: density, specific heat,
equivalent weight)
Extensive Property - Answer -properties dependent of mass (ex: volume and mass)
For a piece of wood having:
Length = 10.35 cm
Width = 6.42 cm
Height = 1.90 cm
Mass = 74.212 g
Calculate the density - Answer -d = m / (lxwxh) = (74.212 g) / (10.35)*(6.42)*(1.90) =
0.587 g/cm^3
What are the units of density? - Answer -g/mL and g/cm^3
What are the units of specific gravity? - Answer -it is unitless
You must bring your lab manual to every lab session - Answer -True
Safety glasses can be removed once you are entering data in your lab notebook -
Answer -False
You must wear full coverage shoes at all time in lab - Answer -True
You are allowed to pipet out liquids by mouth - Answer -False
You should use glass containers, such as beakers, to collect ice out of an ice machine -
Answer -False
Liquid organic waste can go down the drain - Answer -False
At what temperature is water most dense? what is its physical state at that temperature
and the numeric value for its density? - Answer -4 degrees celsius, liquid, 1 g/mL
What is the volume occupied by 10 g of Iron? DFe = 7.87 g/cm^3 - Answer -d = 10 g /
v; d = 7.87 g/cm^3 = 1.27 cm^3
Intensive (I) or Extensive (E) property?
1. Temperature
2. Mass
3. Density
4. Color
5. Boiling Point - Answer -1. = I
2. = E
3. = I
4. = I
