CHEM 14BL Kinetics Post Lab: The Reaction of
Red Food Color with Bleach | 2025 Latest Update
| 100% Correct – UCLA.
Laboratory Equipment and Measurements: Pre & Post Labs - answer-2 -->12
Which one of the following figures best represents the expected result when
three immiscible liquids are placed in a graduated cylinder together. The
density of liquid A is 0.89 g/mL, while liquid B is 1.00 g/mL, and liquid C is 3.89
g/mL. - answer-Liquid C (bottom) --> B --> A
(4)
You wish to determine the density of a die (dice). To do this you must measure
its mass and volume. To measure its mass you use an available balance. After
ensuring that the balance is properly zeroed, you place a weigh boat on the
balance and record its mass of 0.55 grams. Next you place the dice in the
weigh boat on the balance pan and estimate the total mass of the dice and
weigh boat to be 3.01 grams. What is the mass of the dice? - answer-3.01
(total mass of the dice and the weigh boat) - 0.55 (mass of the weigh boat) =
2.46 grams
Calculate the percent NaI in the original sample mixture. - answer-19.7%
(.95/4.82)
,^
Calculate the percent Mg(OH)2 in the original sample mixture. - answer-25.1%
(1.21/4.82)
^^
Calculate the percent BaSO4 in the original sample mixture. - answer-42.3%
(2.04/4.82)
^^^
Calculate the total percent recovery based on the combined masses that were
recovered. - answer-87.1%
(42.3+25.1+19.7)
A mixture of NaCl, SiO2, and CaCO3 is separated following the procedure given
in this experiment. Indicate how each of the following procedural changes
would affect the amount of the specified substance recovered. Briefly explain.
Hint: Refer to Table 1 for Solubility & Reactivity
The recovery of CaCO3 was attempted by adding 3M H2SO4 instead of 3M HCl
to the SiO2/CaCO3 residue. - answer-If 3M H2SO4 was added instead of 3M
HCl, CaSO4 (not water soluble) will be formed instead of CaCl2 (which is water
soluble). As a result much of the CaCO3 will not be filtered out and will instead
stay behind with the SiO2 (which would not have reacted to either acid). Less
CaCO3 would be recovered.
, The recovery of CaCO3 was attempted by adding 1M KNO3 solution instead of
1M K2CO3 solution to the filtrate, containing aqueous CaCl2. - answer-The
insoluble CaCO3 would not form. Instead all the compounds formed would be
water soluble and therefore could not be removed using vacuum or gravity
filtration. As a result, no CaCO3 would be recovered
Could you separate the components of a mixture Mg(OH)2 and Zn(OH2) by
using 3 M HCL? Briefly explain your answer.
post lab question 1 for table - answer-No, because both components are
soluble in 3M HCl, and would therefore not be separated in that way.
Go a little further in your explanation. Make it clear to someone why them
both dissolving is a problem for a separation.
Briefly describe how you could separate the components of a mixture of
benzoic acid and Na2SO4 and recover the two separated substances. - answer-
I could use extraction with cold water to remove benzoic acid (non-soluble in
cold water) from the Na2SO4 (soluble in cold water). Filtration could then
remove the dissolved Na2SO4 with the water by using filter paper, and the
benzoic acid would be left behind on top of the paper. Then evaporation (with
a hot plate) could be used to remove the water from the Na2SO4. Similarly, left
over water can be evaporated from the benzoic acid using a bunsen burner.
A mixture was known to contain three of the four compounds in the table.
After the mixture of the three solids was extracted with hot water and filtered,
Compound A was obtained by evaporating the filtrate to dryness. When 3M
HCl was added to the solid residue, a clear solution resulted. After adding
excess 3M NaOH solution to the acid solution, a precipitate was formed. After
filtration, the insoluble solid was found to be Compound B. Compound C was
Red Food Color with Bleach | 2025 Latest Update
| 100% Correct – UCLA.
Laboratory Equipment and Measurements: Pre & Post Labs - answer-2 -->12
Which one of the following figures best represents the expected result when
three immiscible liquids are placed in a graduated cylinder together. The
density of liquid A is 0.89 g/mL, while liquid B is 1.00 g/mL, and liquid C is 3.89
g/mL. - answer-Liquid C (bottom) --> B --> A
(4)
You wish to determine the density of a die (dice). To do this you must measure
its mass and volume. To measure its mass you use an available balance. After
ensuring that the balance is properly zeroed, you place a weigh boat on the
balance and record its mass of 0.55 grams. Next you place the dice in the
weigh boat on the balance pan and estimate the total mass of the dice and
weigh boat to be 3.01 grams. What is the mass of the dice? - answer-3.01
(total mass of the dice and the weigh boat) - 0.55 (mass of the weigh boat) =
2.46 grams
Calculate the percent NaI in the original sample mixture. - answer-19.7%
(.95/4.82)
,^
Calculate the percent Mg(OH)2 in the original sample mixture. - answer-25.1%
(1.21/4.82)
^^
Calculate the percent BaSO4 in the original sample mixture. - answer-42.3%
(2.04/4.82)
^^^
Calculate the total percent recovery based on the combined masses that were
recovered. - answer-87.1%
(42.3+25.1+19.7)
A mixture of NaCl, SiO2, and CaCO3 is separated following the procedure given
in this experiment. Indicate how each of the following procedural changes
would affect the amount of the specified substance recovered. Briefly explain.
Hint: Refer to Table 1 for Solubility & Reactivity
The recovery of CaCO3 was attempted by adding 3M H2SO4 instead of 3M HCl
to the SiO2/CaCO3 residue. - answer-If 3M H2SO4 was added instead of 3M
HCl, CaSO4 (not water soluble) will be formed instead of CaCl2 (which is water
soluble). As a result much of the CaCO3 will not be filtered out and will instead
stay behind with the SiO2 (which would not have reacted to either acid). Less
CaCO3 would be recovered.
, The recovery of CaCO3 was attempted by adding 1M KNO3 solution instead of
1M K2CO3 solution to the filtrate, containing aqueous CaCl2. - answer-The
insoluble CaCO3 would not form. Instead all the compounds formed would be
water soluble and therefore could not be removed using vacuum or gravity
filtration. As a result, no CaCO3 would be recovered
Could you separate the components of a mixture Mg(OH)2 and Zn(OH2) by
using 3 M HCL? Briefly explain your answer.
post lab question 1 for table - answer-No, because both components are
soluble in 3M HCl, and would therefore not be separated in that way.
Go a little further in your explanation. Make it clear to someone why them
both dissolving is a problem for a separation.
Briefly describe how you could separate the components of a mixture of
benzoic acid and Na2SO4 and recover the two separated substances. - answer-
I could use extraction with cold water to remove benzoic acid (non-soluble in
cold water) from the Na2SO4 (soluble in cold water). Filtration could then
remove the dissolved Na2SO4 with the water by using filter paper, and the
benzoic acid would be left behind on top of the paper. Then evaporation (with
a hot plate) could be used to remove the water from the Na2SO4. Similarly, left
over water can be evaporated from the benzoic acid using a bunsen burner.
A mixture was known to contain three of the four compounds in the table.
After the mixture of the three solids was extracted with hot water and filtered,
Compound A was obtained by evaporating the filtrate to dryness. When 3M
HCl was added to the solid residue, a clear solution resulted. After adding
excess 3M NaOH solution to the acid solution, a precipitate was formed. After
filtration, the insoluble solid was found to be Compound B. Compound C was
