Robert Boyle



Boyle's Law

Introduction:

Robert Boyle who is also referred to as "Father of Modern Chemistry" did a lot of different work in the field of physics and chemistry during his lifetime. In 1660, Boyle published a scientific report, The Spring and Weight of the Air in which he first described different experiments he created using a new vacuum pump which he designed.

In 1662, Boyle published his second version of The Spring and Weight of the Air. In this version with help from his assistant Robert Hooke, this is were he described the inverse relationship between pressure and volume. This relationship is now known as Boyle's Law. Boyle's Law states that pressure and volume are inversely proportional to each other. As the pressure increases the volume decreases and vice versa. He made these observations by using Mercury in a J-tube and made measurements of the volume of the trapped gas at pressures both higher and lower then normal atmospheric pressure.

Boyle expressed his results in a relationship that is known as Boyle's equation: P1V1 = P2V2 assuming the temperature remains constant.

Purpose:

The purpose of this exercise is using Boyle's original data obtained from the website http://webserver.lemoyne.edu/faculty/giunta to verify that Boyle's Law stating that pressure and volume are inversely proportional to each other assuming temperature remains constant is true.


Data:

Figure 1: Boyle's Data



Figure 2: Pressure vs. Volume Graph



Figure 3: Pressure vs. Inverse Volume



Analysis:

To verify Boyle’s Law which states that pressure and volume are inversely proportional to each other assuming the temperature remains constant is accurate, I needed to obtain a data table that Boyle used in 1662 to present his findings. This data was obtained from the website http://webserver.lemoyne.edu/faculty/giunta and the information was placed into a excel data table and a graph was constructed.

Figure 2 is a pressure versus volume graph from Boyle’s original experiment. The data to create this graph was taken from figure 1. The graph shows that as volume decreases the pressure increases. The R² value of 0.9978 shows the trendline fits the regression very close to perfect. Since the trendline fits the regression this shows that Boyle’s conclusion that pressure and volume are inversely proportional to each other is accurate.

Figure 3 is a pressure versus inverse volume graph. If Boyle’s Law is accurate when graphing pressure versus inverse volume the graph will have a linear relationship assuming the two variables are inversely related. The R² value of 1 and the linear line shows that Boyle’s Law is true and that pressure and volume are inversely related.   

Overall, the analysis of Boyle’s original data went presented in graph form clearly shows that his conclusion that pressure and volume are inversely related assuming temperature is constant is accurate. Both Figure 2 and 3 demonstrate this fact. In figure 2 the as the volume decreases the pressure increases. In Figure 3 it shows that one variable versus an inverse variable will yield a linear function which is shown in the graph. The R² value from figure 2 is close to perfect and the R² value for figure 3 is perfect which also concludes that Boyle’s Law is correct and pressure is inversely to volume or vice versa.