Elara Breckenridge
Lab Partner: Justine Powell
10/22/2018
Which Alkali Metal Carbonate?
This lab used gravimetric analysis with vacuum filtration, simple weight loss recording,
and a flame test to determine the composition of the unknown solid. All three methods should
point out the molar mass, reactivity and flammability reaction of the unknown solid. Solid
number 1 weighed 0.417 g after the Gravimetric test, which started with 0.5 g. An average of
1.046 g of carbon dioxide was lost in the simple weight loss trials. In the flame test, a bright
purple was produced when the the unknown was burnt.
Introduction
This lab was meant to teach more of the use of stoichiometry, the principle of the
conservation of mass, and metal reacting to a flame. Finding a metal alkali carbonate is mostly
about finding the metal, as the carbonate is a known within the unknown. Unknown Alkali
Carbonate was found to be Potassium (K) Carbonate after all of these tests.
Data
During the Gravimetric test, 0.5 grams of the unknown alkali carbonate were dissolved
into 50 mL of distilled water, then 20 mL of 1.0 M Barium Carbonate were added. The mixture
was heated and simmered. After this is was put through a vacuum filter. Great care was taken to
recover all residual solids, but this was a source of error. The filter papers were allowed to dry
before being massed to find the amount of the unknown that was recovered by the filtration
system. The amount of unknown alkali carbonate 1 that was recovered was 0.417 grams.
The simple weight loss trials had 0.5 grams of the unknown carbonate reacting with
approximately 20.0 mL of HCI. After the release of the carbon dioxide, the molar mass of the
unknown alkali carbonate can be found with stoichiometry. For the first trial, there was a release
of 2.891 grams of . This
C O 2seemed to be the most accurate of all three trials. Trial two had a
release of 0.169 grams of C, and
O 2 trial three had 0.078 grams of C O .2 I was able to find a
tentative molar mass of about 128 grams/mole for our unknown alkali carbonate.
When conducted with a control of just the toothpick, the flame test produced a bright
orange flame. When the test was performed again it created a light pink, lavender hue, and the
second and third trials produced a vibrant purple, a sign for Potassium (K).
Results
Unknown Alkali Carbonate is believed to be Potassium Carbonate. The Gravimetric
analysis revealed 0.417 grams of after filtration. The equation is as follows.
B aCI2 + M 2 CO 3 → B aCO 3 + M 2 CI
Lab Partner: Justine Powell
10/22/2018
Which Alkali Metal Carbonate?
This lab used gravimetric analysis with vacuum filtration, simple weight loss recording,
and a flame test to determine the composition of the unknown solid. All three methods should
point out the molar mass, reactivity and flammability reaction of the unknown solid. Solid
number 1 weighed 0.417 g after the Gravimetric test, which started with 0.5 g. An average of
1.046 g of carbon dioxide was lost in the simple weight loss trials. In the flame test, a bright
purple was produced when the the unknown was burnt.
Introduction
This lab was meant to teach more of the use of stoichiometry, the principle of the
conservation of mass, and metal reacting to a flame. Finding a metal alkali carbonate is mostly
about finding the metal, as the carbonate is a known within the unknown. Unknown Alkali
Carbonate was found to be Potassium (K) Carbonate after all of these tests.
Data
During the Gravimetric test, 0.5 grams of the unknown alkali carbonate were dissolved
into 50 mL of distilled water, then 20 mL of 1.0 M Barium Carbonate were added. The mixture
was heated and simmered. After this is was put through a vacuum filter. Great care was taken to
recover all residual solids, but this was a source of error. The filter papers were allowed to dry
before being massed to find the amount of the unknown that was recovered by the filtration
system. The amount of unknown alkali carbonate 1 that was recovered was 0.417 grams.
The simple weight loss trials had 0.5 grams of the unknown carbonate reacting with
approximately 20.0 mL of HCI. After the release of the carbon dioxide, the molar mass of the
unknown alkali carbonate can be found with stoichiometry. For the first trial, there was a release
of 2.891 grams of . This
C O 2seemed to be the most accurate of all three trials. Trial two had a
release of 0.169 grams of C, and
O 2 trial three had 0.078 grams of C O .2 I was able to find a
tentative molar mass of about 128 grams/mole for our unknown alkali carbonate.
When conducted with a control of just the toothpick, the flame test produced a bright
orange flame. When the test was performed again it created a light pink, lavender hue, and the
second and third trials produced a vibrant purple, a sign for Potassium (K).
Results
Unknown Alkali Carbonate is believed to be Potassium Carbonate. The Gravimetric
analysis revealed 0.417 grams of after filtration. The equation is as follows.
B aCI2 + M 2 CO 3 → B aCO 3 + M 2 CI
