Date:2/15/2015
Exp 1: Observations of Chemical Changes
Lab Section: 73426
Data Tables:
Part 1:
Chemicals
Well No.
Observations of the Reaction
A.
NaHCO3 + HCl
A1
Bubble formation but no color change present
B.
HCl + BTB
B1
Turned a light orange color
C.
NH3 (NH4OH)+ BTB
C1
Turned blue
D.
HCl + blue dye
D1
Turned green
E.
Blue dye + NaOCl
E1
No change occurred after adding NaOCl.
with the 1 drop of HCl
After adding the HCl a color change occurred. It became 3 different colors green, blue, and orange before changing to a solid faint yellow color.
F.
NaOCl + KI
F1
Turned a light brown after adding KI
with 1 drop of starch
Became black after starch was added.
G.
KI + Pb(NO3)2
G1
Turned a yellow color with precipitate on bottom.
H.
NaOH + phenolphthalein
H1
Turned a very dark pink.
I.
HCl + phenolphthalein
A12
Became cloudy
J.
NaOH + AgNO3
B12
Turned a brownish color with precipitate.
K.
AgNO3 + NH3 (NH4OH)
C12
No change.
after exposure to bright light
Nothing happened.
L.
NH3 (NH4OH)and CuSO4
D12
Turned sky blue and a precipitate was formed
Part F: Testing of Various Foods with the NaOCl + KI solution
Foods
Presence or Absence of Starch
Potato
Present
Bread
Present
Romain Lettuce
Absent
Vanilla Cake
Present
Ranch Dressing
Present
Mayonnaise
Present
Smoked Turkey
Present
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
Apple Cider Vinegar+BTB
A8
Turned Blue (basic)
Hand Sanitizer+BTB
H9
Turned orange (more acidic)
Bleach+BTB
G10
Turn a faint yellow (acidic)
Conclusion: The purpose of the Observation of Chemical Changes lab was to be able to observe and identify properties of chemical reactions also recognize these chemical properties in household chemicals.
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? I would test this product the same way I tested other substances in this experiment. In the 96 well-plate I would use two drops of the product and add two drops of the hydrochloric acid. What would determine whether NaHCO3 is present is if bubbles form.
B. Looking at the household chemicals you tested with bromthymol blue, what can you deduce from the test results for