Lab 4 - Gases

# Lab 4 - Gases - 14 Chem 111 Gas Laws 14 Gas Laws Scientists...

This preview shows pages 1–4. Sign up to view the full content.

Chem 111, Gas Laws 14 Gas Laws Scientists love to determine relationships between two or more concepts. By knowing a specific relationship, scientists can control their experiments and make predictions concerning future experiments. This helps to limit "chaos" from taking over the lab and saves a lot of time by pointing the scientist in the right direction. Two relationships that we will be trying to figure out is between pressure and volume of a gas at room temperature, and the pressure and volume of a gas at different temperatures. We will use the computer and some sophisticated graphing techniques to unravel this conceptual relationship on a qualitative as well as a quantitative level. Lastly, we will unify these relationships into a nice little package called a physical law.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Chem 111, Gas Laws 16 Water transmits pressure without loss, an observation first made by the French scientist Blaise Pascal in the 1600s. Consider the forces at the liquid/gas interface in burette on the left in Figure 1. Since the water is stationary, the pressure of the trapped gas pushing down on the water must be the same as the pressure the water surface is exerting pushing up. In other words, the forces must be balanced. The pressure the water surface is exerting pushing up comes from the undiminished force of the atmosphere on the burette on the right being transmitted by the water. Thus the pressure of the trapped air on the left must be the same as atmospheric pressure. Now consider Figure 2, where the level of the water in the two columns is not equal. Here the pressure exerted up is equal to the pressure of the atmosphere plus the hydrostatic pressure arising from the difference in height of the water column in the two tubes (see Figure 2), and so the pressure of the trapped air is P = P atm + P hydrostatic (1) where P = trapped gas pressure, P atm = atmospheric pressure, P hydrostatic = hydrostatic pressure Figure .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 09/21/2011 for the course CHEMISTRY 134 taught by Professor Lesliemcmillan during the Spring '11 term at ASU.

### Page1 / 11

Lab 4 - Gases - 14 Chem 111 Gas Laws 14 Gas Laws Scientists...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online