Observation of Chemical Change

Topics: Chemistry, Blue, Chemical reaction Pages: 5 (1072 words) Published: September 22, 2014
Laboratory Report
Title: Observation of Chemical Change
Course: General College Chemistry

Purpose

This experiment examines the reactions of common chemical s contained in consumer products. The purpose is to observe the macroscopic changes that these chemicals undergo. The goals of the experiment observe properties of chemical reactions and to associate chemical properties with household products.

Procedure

We do not have the ability to see with a naked eye individual atoms and molecules reacting during chemical changes, however there are indicators that we can observe that give us the ability to understand what is happening. In this experiment there were fourteen different chemicals of which were mixed with each other twelve different times and I observed there reactions.

Using a pipet two drops each chemical was deposited into the 24-well plate. The chemical mixtures are noted below in the Data Tables.

Data Tables and Observations

Question/ Well Number
Chemicals
Reactions/Observation

A / A1

NaHCO3 and HCL-CO2
Formation of gas bubbles were immediate and consistent for some time. No color change, clear. Easier to see under black paper.

B / A2

HCI and BTB
After adding BTB the color automatically changed to a copper color. The color was more pronounced under the white piece of paper.

C / A3

NH3 and BTB
Color was almost Identical to BTB, dark blue. I expect BTB to turn orange with an acid and blue with a base.

D / A5

HCI and Blue Dye
Automatically turned a dark green. More pronounced with white paper.

E / A6

Blue Dye and NaOCI
The initial reaction was a light blue color, then when one drop of HCL was added it first became clear then turned a yellow/orange color. That yellow stayed concentrated at the top segregated.

F / A7

NaOCI and KI
Automatically turned brown and when the starch was added it turned black.

G / A11

KI and Pb(NO3)
Automatically turned a cloudy yellow color and became more solidified than the other experiments. H / B1
NaOH and phenolphthalein
Automatically turned a bright pink.
I /B2
HCI and phenolphthalein
Clear no reaction. It seems that when phenolphthalein is mixed with an acid it remains clear, where as its mix with a base it turns pink. J /B3
NaOH and AgNO3
Automatically turned brown. Looked thicker than other liquids. K /B4
AgBO3 and NH3
The reaction was clear. After exposure to bright light from my light bulb it turned a dark brown. L /B5
NH3 and CuSO
The reaction was a misty blue color.

Highlighted Observations

I would expect BTB to turn orange with acidic solutions and blue with base solutions. When phenolphthalein is mixed with an acid it remains clear, where as its mix with a base it turns pink. When the starch was added to sodium hypochlorite NaOCI and potassium iodide KI it turned black.

Questions

1. Suppose a household product label says it contains sodium carbonate (sodium bicarbonate). How would you test this material for the presence of sodium bicarbonate?

NaHCO3 sodium bicarbonate is a widely known household product otherwise known as baking soda. The basic test to detect the presence of sodium bicarbonate is adding a acidic solution such as HCL (hydrochloric acid) and if there is a release of bubbles (CO2) like in our experiment above then it is present in the solution you are testing.

2. Three household products mixed with bromothymol blue (BTB): a. Green Works from Clorox
i. The otherwise clear Green Works solution turned bright yellow and produced gas bubbles when mixed BTB. ii. The reaction turning yellow would be indicative of an acidic solution when mixed with BTB. b. Windex

i. Other than some bubbles produced there was no significant changes occurred when BTB was added. It did turn a bit darker blue. ii. The result of the mixture indicates that the solution is basic because it turned (stayed) blue. c. Apple Jucie

i. Turned a dark...
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