Observations of Chemical Changes by the Use of Acids and Bases

Experiment 1: Observations of Chemical Changes

Title and Identifiers: Observations of Chemical Changes by the use of acids and bases.

Purpose / Objective:

To observe the small changes that occur in chemical reactions and attempt to interpret the changes of the atoms and molecules that allow for these small changes to happen; and to associate these chemical properties with household products. We will also learn how to separate mixtures.

Procedural Outline:

To perform this experiment, I took the 24-well plate and placed 10 drops of distilled water into well #A1. Then I took the HCl from the Chemical bag and added 2 drops to well A1. Next, I stirred the water and the HCl in the well with a toothpick to ensure that the HCl was diluted. Then I labeled the pipet as HCl and sucked up the diluted HCl and placed the pipet upside down in a well plate. For Ammonia and Sodium Hydroxide, I did the same procedure in well #A2 and A3. Then I grabbed a 96-wellplate, the solutions in the pipets that contain them that I just created, a piece of white paper, a piece of black paper, and the chemicals from the Observation of Chemical Changes Experiment Bag.

For each combination mentioned bellow I used a different 96-well plate, and placed 2 pipet drops of the first chemical in one well and then added 2 drops of the second chemical. After combining the chemicals, I observed the mixture against white and dark backgrounds by slipping white and black paper underneath the well plate. For every reaction, I wrote down the chemical combination, the well number, and my observations of the chemical reactions against the white and dark backgrounds. The combinations are as follows:

a) NaHCO3 and HCl

b) HCl and BTB

c) NH3 and 1 drop of BTB

d) HCl and FDC Blue Dye#1

e) FDC Blue Dye#1 and NaOCl. Observe, then add 1drop of HCl.

f) NaOCl and KI . Observe, then add 1 drop of starch (shake well before using).

g) KI and Pb(NO3)2

h) NaOH and phenolphthalein.

i) HCl and phenolphthalein

j) NaOH and AgNO3

k) AgNO3 and NH3

l) NH3 and CuSO4(Copper(II)sulfate)

Then I used a toothpick to stir up the chemical and recorded the observations:

Reactions Expected:

Table 1

chemicals Well # Reaction on white Reaction on black

NaHCO3