Chemical Changes Lab
Name: Marisa Malazzo
Date: 7/17/14
Exp 1: Observations of Chemical Changes
Lab Section: 76426
Data Tables:
Part 1:
Chemicals
Well No.
Observations of the Reaction
A.
NaHCO3 + HCl
no color change, some small bubbles formed
B.
HCl + BTB
changed a yellowish orange color, no bubbles or precipitation
C.
NH3 + BTB
changed a blue color
D.
HCl + blue dye
changed a green color
E.
Blue dye + NaOCl
no chemical change, only blue color appeared
with the 1 drop of HCl
blue green then changed to yellow
F.
NaOCl + KI
turned blackish brown
with 1 drop of starch
turned black then back to yellowish brown
G.
KI + Pb(NO3)2
bright yellow and almost like it had pulp consistency to it …show more content…
H.
NaOH + phenolphthalein
bright purple magenta and thick liquid consistency
I.
HCl + phenolphthalein
no color change or physical changes
J.
NaOH + AgNO3
turns light brown then forms brown chunks in the liquid
K.
AgNO3 + NH3
color stayed clear
after exposure to bright light
dark brown and appeared to have some substance separation
L.
NH3 and CuSO4
cloudy light blue color then separated into white and blue segments
Part F: Testing of Various Foods with the NaOCl + KI solution
Foods
Presence or Absence of Starch
peanut butter absence of starch
chip presence of starch
bread presence of starch cookie presence of starch french fry
presence of starch chocolate bar
absence of starch ice cream
absence of starch
Part 2:
Household Chemicals with Bromthymol Blue
Use the empty pipet in the Auxiliary Supplies Bag to test several (at least 3) household items including household cleaning products with bromothymol blue. Rinse the pipet well before using it on the next household chemical. When finished with this experiment rinse the pipet well and return it to the Auxiliary Bag for use in future experiments. Name the items tested and record their results.
Household Chemicals
Well No.
Observations of the Reaction
Windex
the chemicals turn pink when mixed together
Bleach
the chemicals turn pink when mixed together
Ammonia
no physical reaction to see
Conclusion:
The objective of this experiment was to infer what happens when different chemicals are mixed together.
After completing this experiment several of the chemicals just simply changed colors. The main colors shown were blue, yellow, pink, green, and a brownish black. A few of the reactants did not change to a different color at all, but did show little signs of bubbles at the surface.
The household items had similar reactions as the chemicals provided in the kit as far as color changes and slight physical precipitation. I attempted to be sure and drop the same number of drops in the beaker when testing the reactions to reduce the percent error throughout the experiment. I do believe the goal of this experiment was achieved because I did learn how to decipher between acids and bases as far as the color change during the reactions.
The experiment was very helpful in learning how the chemicals do react with each other. Some chemicals change colors, some chemicals remain the same color, but bubble or precipitate, while others might no have any apparent physical change at all. All chemicals react differently to each other in different situations, lighting, temperatures and surroundings. Learning about these different chemicals was very intriguing to me and a fun experiment to do as
well.
Questions and Problems:
A. Suppose a household product label says it contains sodium hydrogen carbonate (sodium bicarbonate, NaHCO3). How would you test this material for the presence of sodium bicarbonate?
The best thing would be to use HCl to test the chemical and see if there are any apparent bubbles within the two.
B. Looking at the household chemicals you tested with bromthymol blue, what can you deduce from the test results for each of the household chemicals?
The chemicals turned a yellowish color when they were mixed with BHB.
C. You found a sample of a solution that you think might be vinegar which is acidic. You are verifying that it is indeed vinegar and you add a few drops of phenolphthalein. The sample turns pink. What does that tell you about this sample?
The color pink demonstrates that it is a base.
D. You suspect dissolved silver ions in a solution. How would you test this solution to confirm the presence of the silver ions?
In order to discover the presence of silver ions, I would use a sodium chloride solution and wait to see if a white precipitate appears and then rests at the bottom of the beaker.
Date: 7/17/14
Exp 1: Observations of Chemical Changes
Lab Section: 76426
Data Tables:
Part 1:
Chemicals
Well No.
Observations of the Reaction
A.
NaHCO3 + HCl
no color change, some small bubbles formed
B.
HCl + BTB
changed a yellowish orange color, no bubbles or precipitation
C.
NH3 + BTB
changed a blue color
D.
HCl + blue dye
changed a green color
E.
Blue dye + NaOCl
no chemical change, only blue color appeared
with the 1 drop of HCl
blue green then changed to yellow
F.
NaOCl + KI
turned blackish brown
with 1 drop of starch
turned black then back to yellowish brown
G.
KI + Pb(NO3)2
bright yellow and almost like it had pulp consistency to it …show more content…
H.
NaOH + phenolphthalein
bright purple magenta and thick liquid consistency
I.
HCl + phenolphthalein
no color change or physical changes
J.
NaOH + AgNO3
turns light brown then forms brown chunks in the liquid
K.
AgNO3 + NH3
color stayed clear
after exposure to bright light
dark brown and appeared to have some substance separation
L.
NH3 and CuSO4
cloudy light blue color then separated into white and blue segments
Part F: Testing of Various Foods with the NaOCl + KI solution
Foods
Presence or Absence of Starch
peanut butter absence of starch
chip presence of starch
bread presence of starch cookie presence of starch french fry
presence of starch chocolate bar
absence of starch ice cream
absence of starch
Part 2:
Household Chemicals with Bromthymol Blue
Use the empty pipet in the Auxiliary Supplies Bag to test several (at least 3) household items including household cleaning products with bromothymol blue. Rinse the pipet well before using it on the next household chemical. When finished with this experiment rinse the pipet well and return it to the Auxiliary Bag for use in future experiments. Name the items tested and record their results.
Household Chemicals
Well No.
Observations of the Reaction
Windex
the chemicals turn pink when mixed together
Bleach
the chemicals turn pink when mixed together
Ammonia
no physical reaction to see
Conclusion:
The objective of this experiment was to infer what happens when different chemicals are mixed together.
After completing this experiment several of the chemicals just simply changed colors. The main colors shown were blue, yellow, pink, green, and a brownish black. A few of the reactants did not change to a different color at all, but did show little signs of bubbles at the surface.
The household items had similar reactions as the chemicals provided in the kit as far as color changes and slight physical precipitation. I attempted to be sure and drop the same number of drops in the beaker when testing the reactions to reduce the percent error throughout the experiment. I do believe the goal of this experiment was achieved because I did learn how to decipher between acids and bases as far as the color change during the reactions.
The experiment was very helpful in learning how the chemicals do react with each other. Some chemicals change colors, some chemicals remain the same color, but bubble or precipitate, while others might no have any apparent physical change at all. All chemicals react differently to each other in different situations, lighting, temperatures and surroundings. Learning about these different chemicals was very intriguing to me and a fun experiment to do as
well.
Questions and Problems:
A. Suppose a household product label says it contains sodium hydrogen carbonate (sodium bicarbonate, NaHCO3). How would you test this material for the presence of sodium bicarbonate?
The best thing would be to use HCl to test the chemical and see if there are any apparent bubbles within the two.
B. Looking at the household chemicals you tested with bromthymol blue, what can you deduce from the test results for each of the household chemicals?
The chemicals turned a yellowish color when they were mixed with BHB.
C. You found a sample of a solution that you think might be vinegar which is acidic. You are verifying that it is indeed vinegar and you add a few drops of phenolphthalein. The sample turns pink. What does that tell you about this sample?
The color pink demonstrates that it is a base.
D. You suspect dissolved silver ions in a solution. How would you test this solution to confirm the presence of the silver ions?
In order to discover the presence of silver ions, I would use a sodium chloride solution and wait to see if a white precipitate appears and then rests at the bottom of the beaker.