Chemistry 132 Lab 01 Graphing Relationships printable pdf download

Chemistry 132 Lab 01 Graphing Relationships

132 Lab 01

Western Carolina University

HEM

Name __________________________

Lab Section______________

Chemistry 132 Lab 01

Graphing Relationships

In this experiment you will investigate relationships involving the dimensions, volumes, and masses

of objects. First, you will measure several of these parameters, then the data will then be graphed in

order to look for any patterns in the data. This experiment discusses several types of graphs that

you will encounter in this course, and is designed to help you interpret what the graphs mean. You

will apply what you learn in this experiment to Lab #2 (Mass/Volume Relationships).

Be sure to log onto Chem21 Labs, print out the data sheet (“PDF Lab Guide”) and bring it to lab.

Introduction

Scientists commonly graph data in order to discover relationships between variables. Typically the

vertical axis is referred to as the y-axis and the horizontal axis is called the x-axis. The relationship

between the variable plotted on the y-axis and the variable plotted on the x-axis can be determined

by the shape of the graph obtained.

One type of graph you may encounter is shown in Figure 1. Here the data points approximate a

horizontal line. This indicates that the variable on the y-axis has no relationship to (is independent

of) any change in the variable on the x-axis. Figure 1 is a graph of the speed (velocity) of an

automobile as a function of time. As can be seen in this example, the speed of the automobile is

approximately 60 miles per hour (mph) over the course of ten minutes, hence the y-axis variable is

said to be independent of the x-axis variable.

For Figure 1, the line that was drawn does not go directly through all of the data points. The line is

the best linear fit to the data, representing a general trend for this set of data.

Time, minutes

Figure 1. The speed of an automobile as a function of time.

Chemistry 132 Lab 01 Graphing Relationships