CHM 113 QUESTIONS & ANSWERS
CORRECT 100%
Density - ANSWERmass divided by volume
Specific Gravity - ANSWERThe ratio of the density of a substance to the density of
water
Intensive property - ANSWERProperties independent of mass. Examples: density,
specific heat, equivalent weight
Extensive property - ANSWERProperties dependent of mass. Example: volume and
mass
Volume of a cylinder - ANSWERV = pi(r)^2h
If you get N grams of BaSO4 in the end of the reaction, there should be how many
grams of sulfate in the unknown powder? - ANSWER(N*(233g/mol-137g/mol)/233 =
N*96/233
During the conductimetric titration why do you need to rinse the reagent reservoir
with H2SO4 solution before transferring 40 m: of the H2SO4 to the reagent
reservoir? - ANSWERTo get rid of the H2O that could interfere
During the conductimetric titration of BaSO4, the graph resembles a - ANSWERV
shape with volume on the x-axis and conductivity on the y-axis.
Mass of water displaced by a rock with 143g in air and 82 g in water -
ANSWERMass of water displaced = Mass of rock in air - mass of rock in water
Volume of water displaced by a rock - ANSWERV = mass of water displaced divided
by density of water
Density of rock with 143g in air, 82 g in water - ANSWER= mass of rock in air divided
by the volume it displaces in water
If a piece of PVC is suspended in solution than the density of the PVC is -
ANSWERequal to the density of the solution
Which has a greater density: water or ice? - ANSWERWater (Ice floats on water)
What are the units of density? - ANSWERg/mL and g/cm^3
Why is density important? - ANSWERIt identifies a substance
What is the conversion factor of cm^3 and mL - ANSWER1 cm^3 = 1 mL
, What is the normal order of density for the states of matter? - ANSWERGas is the
least dense, liquid is more dense and solid is the most dense.
What property of adipic acid is used in the separation during the adipic acid lab? -
ANSWERsolubility
What is the formula for Adipic Acid? - ANSWERH2C6H8O4
What is the unit of specific heat? - ANSWERthere is no unit
What does density tell us? - ANSWERDensity relates information on how the atoms
or molecules that make it up are arranged in space. Substance with larger density is
more tightly packed than the substance with smaller one.
What is the structure of adipic acid? - ANSWERHOOCCH2CH2CH2CH2COOH
What is adipic acid used for? - ANSWERProduction of nylon; additive to drinks
Solubility of Adipic Acid - ANSWERAdipic acid's solubility is temperature dependent.
It is more soluble in hot water and slightly soluble in cold water. This property is the
principle of recrystallization of adipic acid.
What impurities make the crude adipic acid brown? - ANSWEROxidized compounds
and fine carbon particles.
What substance absorbs the impurities? - ANSWERCharcoal. One scoop is added
to the beaker.
Why is fluted filter paper used instead of flat filter paper? - ANSWERIt has a larger
surface area for contact with the solution, thus leading to a more rapid rate of
filtration.
Why was the adipic acid heated? - ANSWERTo dissolve is completely in hot water.
Why was the adipic acid cooled? - ANSWERSo the acid will crystallize
How do you calculate percent yield of adipic acid? - ANSWERWeight of pure adipic
acid/Weight of crude adipic acid x 100
What is the difference in melting point between Crude and Pure adipic acid? -
ANSWERPure adipic acid will melt at a temperature close to the literature value. It
will have a narrow melting point range. The purer the compound is, the smaller is
melting point depression (Literature value - experimental value) and the smaller is
melting point range. The crude will have a large melting point range and the melting
point will be less than the pure on. The impurity interrupts the normal intermolecular
force.
How much pure adipic acid was recovered if there was a crude sample of adipic acid
that weighed 20.421 g and a yield of pure adipic acid of 73.5%? -
ANSWERPure/Crude x 100 = 73.5%
CORRECT 100%
Density - ANSWERmass divided by volume
Specific Gravity - ANSWERThe ratio of the density of a substance to the density of
water
Intensive property - ANSWERProperties independent of mass. Examples: density,
specific heat, equivalent weight
Extensive property - ANSWERProperties dependent of mass. Example: volume and
mass
Volume of a cylinder - ANSWERV = pi(r)^2h
If you get N grams of BaSO4 in the end of the reaction, there should be how many
grams of sulfate in the unknown powder? - ANSWER(N*(233g/mol-137g/mol)/233 =
N*96/233
During the conductimetric titration why do you need to rinse the reagent reservoir
with H2SO4 solution before transferring 40 m: of the H2SO4 to the reagent
reservoir? - ANSWERTo get rid of the H2O that could interfere
During the conductimetric titration of BaSO4, the graph resembles a - ANSWERV
shape with volume on the x-axis and conductivity on the y-axis.
Mass of water displaced by a rock with 143g in air and 82 g in water -
ANSWERMass of water displaced = Mass of rock in air - mass of rock in water
Volume of water displaced by a rock - ANSWERV = mass of water displaced divided
by density of water
Density of rock with 143g in air, 82 g in water - ANSWER= mass of rock in air divided
by the volume it displaces in water
If a piece of PVC is suspended in solution than the density of the PVC is -
ANSWERequal to the density of the solution
Which has a greater density: water or ice? - ANSWERWater (Ice floats on water)
What are the units of density? - ANSWERg/mL and g/cm^3
Why is density important? - ANSWERIt identifies a substance
What is the conversion factor of cm^3 and mL - ANSWER1 cm^3 = 1 mL
, What is the normal order of density for the states of matter? - ANSWERGas is the
least dense, liquid is more dense and solid is the most dense.
What property of adipic acid is used in the separation during the adipic acid lab? -
ANSWERsolubility
What is the formula for Adipic Acid? - ANSWERH2C6H8O4
What is the unit of specific heat? - ANSWERthere is no unit
What does density tell us? - ANSWERDensity relates information on how the atoms
or molecules that make it up are arranged in space. Substance with larger density is
more tightly packed than the substance with smaller one.
What is the structure of adipic acid? - ANSWERHOOCCH2CH2CH2CH2COOH
What is adipic acid used for? - ANSWERProduction of nylon; additive to drinks
Solubility of Adipic Acid - ANSWERAdipic acid's solubility is temperature dependent.
It is more soluble in hot water and slightly soluble in cold water. This property is the
principle of recrystallization of adipic acid.
What impurities make the crude adipic acid brown? - ANSWEROxidized compounds
and fine carbon particles.
What substance absorbs the impurities? - ANSWERCharcoal. One scoop is added
to the beaker.
Why is fluted filter paper used instead of flat filter paper? - ANSWERIt has a larger
surface area for contact with the solution, thus leading to a more rapid rate of
filtration.
Why was the adipic acid heated? - ANSWERTo dissolve is completely in hot water.
Why was the adipic acid cooled? - ANSWERSo the acid will crystallize
How do you calculate percent yield of adipic acid? - ANSWERWeight of pure adipic
acid/Weight of crude adipic acid x 100
What is the difference in melting point between Crude and Pure adipic acid? -
ANSWERPure adipic acid will melt at a temperature close to the literature value. It
will have a narrow melting point range. The purer the compound is, the smaller is
melting point depression (Literature value - experimental value) and the smaller is
melting point range. The crude will have a large melting point range and the melting
point will be less than the pure on. The impurity interrupts the normal intermolecular
force.
How much pure adipic acid was recovered if there was a crude sample of adipic acid
that weighed 20.421 g and a yield of pure adipic acid of 73.5%? -
ANSWERPure/Crude x 100 = 73.5%
