Lab Report Chemical Change

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Lab Report
1/28/13

Observations of Chemical Changes
Page. 14
Objectives:
The objectives of this experiment are:
1. To observe some properties of chemical reactions
2. to associate chemical properties with household products
Background Information:
Chemical changes are often accompanied by physical changes. Three that you should not see in this lab are changes in temperature, presence of a flame, and evolution of light, as when as firefly glows. Three physical changes that indicate a chemical change may have occurred (and that may be seen in this lab) are: 1. Color changes

2. Precipitate (formation of a solid)
3. Formation of gas bubbles
Procedure:
No preliminary dilution of my test chemicals were necessary as Lab Paq provided pre-diluted chemicals. Utilizing the 96-well plate, 2 pipit drops of each chemical were added to the wells in the following combinations: a) NaHCO3+HCl b) HCl+Bromthymol blue c) NH3+1 drop Bromthymol blue d) HCl+blue dye e) Blue dye+NaOCl followed by HCl f) NaOCl+KI followed by various test foods g) KI+Pb(NO3)2 h) NaOH+phenolphthalein i) HCl + phenolphthalein j) NaOH+AgNO3 k) AgNO3+NH3 l) NH3+CuSO4. Along the way, observations were made pertaining to the reactions witnessed. This experiment concluded with testing household chemicals and proper disposal of lab chemicals.  Observations:

CHEMICALS Well # Reaction on white paper Reaction on dark paper a. NaHCO3 + HCl A1 Bubbling Clear Liquid Bubbling Clear Liquid b. HCl + BTB B1 Golden Yellow Clear Liquid Amber Clear Liquid c. NH3 + BTB C1 Royal Blue Clear Liquid Dark Blue Opaque Liquid d. HCl + blue dye D1 Emerald Green Clear Liquid Dark Green Opaque Liquid e. NaOCl + blue dye E1 Bright blue that dissolved to yellow Same; just easier to see then to pale yellow.
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