CHEM 1030L — Experimental Design Week 2 & pH Measurement
Student Name: ______________
Lab Partner(s): ______________
Grade:
Date:
______________
Laboratory Report
Section:
______________
______________ (For Instructor use)
PURPOSE – Experimental Design Day 2
Instructions: Using 2-4 complete sentences written in third person with proper grammar and punctuation, briefly
summarize the purpose of this laboratory exercise. Include the learning objectives and the major outcomes.
Write the purpose of Experimental Design Day 2 activities here…
DATA AND OBSERVATIONS – Experimental Design Day 2
Hint: ALWAYS include units of measurement and the correct number of sig. figs.
Heat
or
No
Heat
Chemical
Reagent
1
Heat
Water
none
2
No
Heat
Water
none
3
Heat
HCl
4
No
Heat
HCl
5
Heat
H2SO4
6
No
Heat
H2SO4
7
Heat
KOH
Test
Tube
#
Mass of
Switchgrass
Powder
8
B
C
MC
No
Heat
No
Heat
No
Heat
No
Heat
Observations
Initial
Glucose
Conc.
# Drops of
Neutralizing
Reagent
Final
pH
KOH
none
none
none
none
none
none
QUESTIONS AND ANALYSIS
1
CHEM 1030L — Experimental Design Week 2 & pH Measurement
Laborato
INSTRUCTIONS: Using one or more complete sentences written in third person with proper grammar and
punctuation, briefly respond to the following questions.
Hint: Remember that points are awarded for each aspect of the question.
1. Write balanced chemical equations for the reactions of KOH with each acid. Include phase labels.
Type the response here...
2. In step 5a, 2 drops of KOH were added to the test tubes that had been treated with HCl. In step 5b, twice
as many drops of 0.5 M KOH were added to the test tubes that had H2SO4. Use complete sentences to
explain why.
Type the response here...
3. Use complete sentences to (a) briefly explain what the cellulase enzyme complex is, (b) list three living
organisms that utilize cellulase enzymes, (c) and the purpose of this cellulase enzyme complex in this
experiment.
Type the response here...
CONCLUSION – Experimental Design Day 2
INSTRUCTIONS: Write an essay, using complete sentences written in third person with proper grammar and
punctuation, to briefly summarize observations made: (1) any changes in the kudzu samples since last week, any
observations made while treating the kudzu samples today, and (3) any problems that occurred today and how
those might affect the final results.
Use paragraphs to separate major ideas, however, do not number the paragraphs.
Type the response here...
------------------------------------------------ PH MEASUREMENT -----------------------------------------------PURPOSE – pH Measurement
Instructions: Using 2-4 complete sentences written in third person with proper grammar and punctuation, briefly
summarize the purpose of this laboratory exercise. Include the learning objectives and the major outcomes.
Write the purpose of the pH Measurement activities here…
DATA AND OBSERVATIONS – pH Measurement
Part A – Measurement of pH of Household Products
pH Measurement
Household Product
1
2
3
Universal
Indicator
pH
Paper
pH
Meter
CHEM 1030L — Experimental Design Week 2 & pH Measurement
Laborato
pH Measurement
Household Product
Universal
Indicator
pH
Paper
pH
Meter
4
5
6
Part B – Buffers
Solution
Step B.1b
Step B.1c
Initial pH
(0 drops
added)
pH after
5 drops
HCl
added
Step
B.1d
pH after
10 drops
HCl
added
Calculate
Change in
pH*
Distilled Water
0.1 M NaCl
Carbonate buffer
Phosphate buffer
*Calculate "Change in pH" by subtracting the Initial pH (0 drops added) from the final
pH (pH after 10 drops added).
Solution
Step B.2b
Step B.2c
Initial pH
(0 drops
added)
pH after
5 drops
HCl
added
Step
B.2d
pH after
10 drops
HCl
added
Calculate
Change in
pH*
Distilled Water
0.1 M NaCl
Carbonate buffer
Phosphate buffer
*Calculate "Change in pH" by subtracting the Initial pH (0 drops added) from the final
pH (pH after 10 drops added).
QUESTIONS AND ANALYSIS
INSTRUCTIONS: Using one or more complete sentences written in third person with proper grammar and
punctuation, briefly respond to the following questions.
Hint: Remember that points are awarded for each aspect of the question.
CHEM 1030L — Experimental Design Week 2 & pH Measurement
1. On average, were the pH values estimated using pH paper and universal indicator close to the values
measured with the pH meter? Should those values be expected to be close?
Type the response here...
2. What was the most basic sample that tested?
Type the response here...
3. What was the most acidic sample that tested?
Type the response here...
4. Were any of the household products found to have a surprising pH? Explain.
Type the response here...
5. In Part B – Buffers, which solution(s) showed the greatest change in pH? Why?
Type the response here...
6. In Part B – Buffers, which solution(s) showed little or no change in pH? Why?
Type the response here...
7. What is the function of a buffer?
Type the response here...
8. Why is important that body fluids are buffered?
Type the response here...
Laborato