EXPERIMENT 0

NAME: Shubham Upadhyay DATE: 09/04/2013

SECTION: 428 TA: Emily Werth

1. Sketch of lab room with all safety items clearly labeled. 10 / 10 pts

In lab notebook pages turned in at end of Experiment 0 lab.

You do not need to provide the sketch here.

2. Sketch of evacuation route in case of fire. 4 / 4 pts

In lab notebook pages turned in at end of Experiment 0 lab.

You do not need to provide the sketch here.

Fill in the remaining parts of the worksheet, items 3-13. You must type your responses;

insert tables using the table tool function in Word and use Microsoft Equation 3.0

(Object, Microsoft Equation 3.0) to insert all formulas and to show all calculations.

3. Answer the following MSDS questions

a. What does the acronym MSDS stand for? 3 / 4 pts

Material Safety Data Kit

b. What type of information does an MSDS sheet provide? 5 / 5 pts

It provides information for:

Product and Company Information

Hazards Identification

Composition

First Aid Measures

Firefighting Measures

Accidental Release Measures

Handling and Storage

Exposure Controls/Personal Protection

Physical and Chemical properties

Stability and Reactivity

Toxicological Information

Ecological Information

Disposal Considerations

Transport Information

Regulatory Information

c. From the MSDS sheet, what is or are the principle routes of 2 / 3 pts

exposure for this substance?

The principle routes of exposure for this substance are inhalation, skin

contact, eye contact, and swallowing.

d. From the MSDS sheet, what is the melting point range for 3 / 3 pts this

substance, with units?

The melting point for this substance is 121-125oC.

e. From the MSDS sheet, what is the physical state of this substance? 3 / 3 pts

The physical state of this substance is white crystalline solid.

4. What is the average and standard deviation for the 10 paper masses 4 / 4 pts

provided by your TA and for the population paper mass data set provided on

Blackboard? Express your answers as Average ± Standard Deviation.

10 Paper Masses:

0.672+0.0063

Population Paper Mass Data Set:

0.660+0.024

5. In this experiment you had a finite data set and a much larger population data set. All

the pieces of filter paper that comprise these data sets came from the same box (lot) of

filter paper.

a. Which data set gives a more accurate representation of the true filter 5 / 5 pts paper

mass for this box of filter paper? Explain.

The much larger population paper mass data set gives a more accurate

representation of the true filter paper mass because the size of the data set

is greater than the sample size of the 10 paper masses.

b. When the number of measurements increases, what happens to the 5 / 5 pts

uncertainty? Do not simply state that it increases or decreases. There is a specific

relationship.

When the number of measurements increases, the uncertainty decreases by

.

6. Using the finite data set, calculate the 95 % confidence interval 6 / 6 pts for

the mass of the filter paper. Use Microsoft Equation 3.0 to write out the formula and

to show your calculations.

7. Construct a table of your pH 4.00 and 8.00 data that you obtained 10 / 10 pts

using “pH Electrode A” and insert it below. Include the average and standard

deviation for each pH.

pH Vial Measured pH Average Standard

Deviation

4 1 4.07 4.11 .025

2 4.12

3 4.12

4 4.12

8 1 7.88 7.98 .071

2 7.98

3 8.03

4 8.03

8. Calculate the relative uncertainty for your pH 4.00 measurements, 4 / 5 pts

obtained using “Electrode A”. Use Microsoft Equation 3.0 to write out the formula

and to show your calculations.

9. The error in the pH readings obtained using “Electrode A” is called 6 / 6 pts what?

The error in the pH readings is called random error.

10. Was the data obtained using “pH Electrode A” accurate, precise, 6 / 6 pts

neither or both? Explain.

The data obtained using Electrode A is both accurate and precise because

the obtained averages are close to the true values and the standard

deviations are small.

11. Construct a table of your pH 4.00 and 8.00 data that you obtained 9 / 9 pts using

“pH Electrode C” and insert it below. Include the average and standard deviation for

each pH.

pH Vial Measured pH Average Standard

Deviation

4 1 5.06 5.06 0.0

2 5.06

3 5.06

4 5.06

8 1 8.95 8.90 0.041

2 8.85

3 8.90

4 8.90

12. How is the error in the pH readings using “Electrode C” different 6 / 6 pts from

the error in the pH reading obtained using “Electrode A”? Be specific.

The error in the pH readings using Electrode C is systematic error, whereas

the error resulting from Electrode A was random error. Due to the results

displayed above, it seems that the pH electrode was calibrated one pH unit

higher than normal. This resulted in all values to be approximately one pH

unit greater than the true value.

13. Was the data obtained using “pH Electrode C” accurate, precise, 6 / 6 pts

neither or both? Explain.

The data obtained using Electrode C is precise but not accurate. It is

precise because the standard deviations for both the pH readings are

relatively small. It is not accurate because the average values (5.06 and

8.90) are greater than the respective true values.