# Lab Techniques

Topics: Density, Water, Pipette Pages: 8 (1839 words) Published: April 26, 2013
Ocean County College
Department of Chemistry
[Laboratory Techniques and Measurements]

Date Submitted:March 15, 2013
Date Performed:March 14, 2013
Lab Section: Chem-181DL1

Purpose
The purpose of this lab is to learn about the International System of Units (SI). This is to help with the familiarity of common laboratory equipment and techniques. Also to help with determining the volume, mass, length, and temperature of a variety of items using common laboratory measurement devices. This is teaching how to combine units to determine density and concentration. The last purpose of the lab is to use laboratory equipment to create serial dilutions and determine the density and concentration of each dilution.

Procedure

Length Measurements:

Gather a metric ruler, CD or DVD, key, spoon, and fork. After those are collected, determining the uncertainty and number of significant figures will help measure each object. Then measure each object in centimeters, then again in millimeters. Lastly, convert each object from millimeters to meters.

|Object |Length (cm) |Length (mm) |Length (m) | |CD or DVD |12 cm |120 mm |.12000 m | |Key |5.1 cm |51mm |.05100 m | |Spoon |17.3 cm |173 mm |.17300 m | |Fork |15.3 cm |153 mm |.15300 m |

Temperature Measurements:

A few things to gather for this part are the 100-mL glass beaker, cup, matches or lighter, burner stand, burner fuel, and a thermometer. Make sure to determine the degree of uncertainty and the number of significant figures. Turn the tap water to hot and let it run for 15 seconds and fill the 100-mL to about 75mL. Measure the hot water wit the thermometer in Celsius. After it is recorded place the beaker on the wire gauze burner stand and place safety glasses on. Remove the cap from the burner fuel and set it aside, then light the burner and place it under the burner stand. Once it is boil measure the temperature. After five minutes measure the temperature again and record. Then take your plastic cup and fill it half way with cold tap water. Measure the temperature, then add a handful of ice cubes to the cup. After a minute stir the water and measure the temperature; do the same after five minutes. Lastly convert the temperature measurements for each of the six water sample from Celsius to Fahrenheit and Kelvin.

|Water |Temperature (C) |Temperature (F) |Temperature (K) | |Hot from tap |40 C |104 F |313.15 K | |Boiling |100 C |212 F |373.15 K | |Boiling for 5 minutes |101 C |213.8 F |374.15 K | |Cold from tap |21 C |69.8 F |294.15 K | |Ice water-1 minute |6 C |42.8 F |279.15 K | |Ice water- 5 minutes |1 C |33.8 F | 274.15 K |

Mass Measurements:

Gather a pen...