Lab 1

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You will be able to type directly on this document. Use as much space as you need. Remember to save the finished document as an” rtf file” or “doc” file(your name and lab number) and attach. ___________

Date of Experiment ___10/6/13_________
Date Report Submitted ____10/7/13_____________

Title:Observation of Chemical Changes
Objectives: To observe some properties of chemical reactions. To associate chemical properties with household products.

Have you made any changes to the procedure? No. Please Explain

Data Tables and Observation: Fill out the data sheet for the experiment and submit with this form. Remember:Lab notes are evidence of your work and of your understanding of the concepts demonstrated in the experiments. They are also the primary basis for your chemistry lab grade. Create a neat document and try to express your thoughts clearly, concisely, and completely.

This lab can be found in the lab manual under “Observations of Chemical Changes.” It is absolutely essential that you read the discussion and review the sections of this lab (and all of the labs) BEFORE you begin the experiment and refer to it when you are working on this write up. Do not take the “short cut” and skim through or you will make errors that will affect your grade. The lab grade is worth 20% of your course grade and can make a difference in your final grade.

Your instructor is prepared to answer questions please use the discussion board so that your very good questions can be answered in a forum from which your fellow students may benefit.

Data Sheet for Experiment # 1 – Observations of Chemical Changes Write down everything you observe, for example: color change (include the color before and after for each step), bubbles, solid formation (precipitate), etc. Indicate the difference, if any, observed on the dark paper versus the white paper. (9 pts)

CHEMICALS
Well No.
Observation on White Paper
Observation on Dark Paper

A
NaHCO3 + HCl
12
Started clear, after adding HCl tiny bubbles.
Clear, bubbles

B
HCl (an acid) + BTB
10
Started clear, transparent yellowish
Looks darker, almost orange

C
NH4OH (a base) + BTB
8
Started clear turned blue
Darker blue

D
HCl + blue dye
6
Started clear, turned green
Dark green
E

NaOCl +blue dye

then add 1 drop of HCl
4
Started clear, turned blue and green
Could see some small bubbles.
F
NaOCl + KI

Then add 1 drop of starch
2
Clear to pale yellow, after adding starch turned black
black

Test at least 4 different food items for the presence of starch. + almond
B2
Stayed the same

+ wheat bread
C2
Turned black

+ cheese
D2
Stayed the same

+ hash brown
E2
Turned black

G
KI (potassium iodide) + Pb(NO3)2 lead nitrate)

1
Turned bright milky yellow

H
NaOH (base) + phenolphthalein
3
Started clear turned dark pink
Dark pink

I
HCl (acid) + phenolphthalein
5
clear
Looks a little milky with tiny bubbles
J
NaOH + AgNO3

7
Started clear and turned a tan/brownish color

K
NH3 (ammonia) or NH4OH + AgNO3

Paper towel result
9
Stayed clear w/ bubbles, did not see any changes to the paper towel. same
L
NH4OH and CuSO4
11
Turned light blue
Looks milky light blue
Before you clean up, answer question #4.
Answer to Question 4: (3 pts)

Describe the results of 3 household cleaning supplies (you may use non-commercial cleaning supplies as well) with the Acid –base Indicators: Bromothymol blue, and phenolphthalein

Product
Indicator
Observation
Conclusion: Acid or Base?
1 Mrs. Meyers counter-top cleaner
Bromothymol blue

Turned green with a few bubbles
base
1 Mrs. Meyers counter-top cleaner
Phenolphthalein

Stayed clear
base
2 Windex
Bromothymol blue

Darker blue
base
2 Windex
Phenolphthalein

Turned pink at first then ended up being clear after a few minutes. base
3 Scrubbing Bubbles Bathroom Cleaner
Bromothymol blue...
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