CHEM 107- General Chemistry Lab I

Balances, Pipets, and Data Analysis Pre-Lab Assignment:

Before coming to lab, you should:

1. Print the handout labeled �Balances, Pipets, and Data Analysis� from the Chem 107 web page. Be sure to bring the handout and data pages with you to lab.� You will turn in the data pages at the end of the lab period.� The procedure you will follow in lab will come from this handout. The reading assignment in the lab manual and text will be used for background information.� Be sure to read the handout, including the background reading assignment, so that you understand all procedures and calculations.
2. Don�t forget to bring your safety goggles to lab.� Laboratory work is not allowed without proper eye protection.
3. Complete the following on a separate sheet of paper.� This pre-lab assignment is due to your instructor at the beginning of lab, and before lab work can begin.

1.� In this lab, you will determine the density of water.� It is a quantitative experiment and thus accuracy is essential.� ��What is the difference between using a graduated cylinder, a volumetric pipet and a graduated pipet for measuring volumes? �What is the best piece of glassware to use to quantitatively measure a known volume of a liquid? (4 pt)

2.� In this lab, you will be required to prepare a graph of mass vs. volume using an Excel spreadsheet from the data you collect in lab.� On what axis will mass be plotted?� On what axis will volume be plotted?� How will you use your graph to determine the density of water?� (4 pts)�

3.� A student needs 118.0 g of ethanol for an experiment, but only has a graduated cylinder available.� If the density of the alcohol is 0.789 g/mL, how many milliliters of ethanol would be needed to get the correct mass?� Show your work, reporting your answer to the correct number of significant figures, and with the correct units. (2 pt)