# Laboratory Techniques and Measurements Essay

2288 Words Mar 13th, 2013 10 Pages
General Chemistry 1
Lab 1: Laboratory Techniques and Measurements

Purpose: The purpose of this lab is to ensure that students are able to understand how to conduct measurements of length, mass, temperature, density and volume using different measuring devices. Students will also learn how to dilute substances by using simple algebra.

Procedure: 1. Prepare a data table similar to Data Table 1 shown below. 2. Choose any three objects that are shorter than the metric ruler to measure, such as a CD, key, spoon, etc. a. Measure the objects’ lengths in centimeters. Estimate to one decimal place. Record the measurements in Data Table 1. b. Measure the objects’ lengths in millimeters. Estimate to one decimal place. Record the
6. Repeat the previous steps for each of the remaining objects.
Density Measurements 1. Record all measurements in a data table similar to Data Table 5 shown below. 2. Calculate the density of water.
Weigh a dry 25 mL graduated cylinder on the digital scale. Record the mass in Data Table 5.
Pour 5 mL of water into the graduated cylinder. Weigh and record the mass of the cylinder and water.
Subtract the mass of the empty graduated cylinder from the mass of the graduated cylinder filled with water. The result is the net mass of the water.
Calculate the density of the water using the formula d= m/V.
Dry the graduated cylinder. 3. Calculate the density of isopropyl alcohol.
Pour 5 mL of isopropyl alcohol into the graduated cylinder. Weigh and record the mass of the cylinder and alcohol.
Calculate the alcohol’s density using the formula d= m/V. 4. Calculate the density of a saturated salt solution.
Use the digital scale to weigh out 5 g of NaCl, table salt. Pour the NaCl into the 100 mL beaker and add 12 mL of warm water. Stir the water/salt mixture for several minutes. Then let any undissolved salt settle to the bottom of the beaker. The liquid is now a saturated solution.
Use an empty short stem pipet to draw up only the saturated solution. Be careful not to draw up any of the solid NaCl crystals.
Measure 5 mL of the saturated solution into an empty graduated cylinder. Draw up two consecutive pipets of saturated solution to reach 5 mL if