Essay on Chm1046 Experiment 2: Intermolecular Forces

All standardizations are performed in triplicate. Weigh out .1000-.1200 gram KIO3. Add 70-80 mL of deionized water. Swirl and dissolve. Add 3 mL of 6M HCl. Swirl and mix. Quickly titrated the brow-red solution with 0.1M Na2S2O3 until it is light yellow. Then add 3.5 mL of starch indicator. Titrate again until the dark color first disappears.

I. LIQUID - Identification of an Unknown Liquid: Using the physical properties of Solubility, Density, and Boiling Point.

B. How does this graph illustrate Boyle’s law? As more pressure is added the volume decreases and the graph shows this because it is decreasing as well. _________________________________

Think about the gas laws we are studying. Boyle’s law tells us that pressure and volume are inversely proportional. Charles’ law states that volume and temperature are directly proportional. We also know that pressure and temperature are directly proportional. Discuss at least one instance in your personal experience where you have seen one or more of these laws in action.

1. Move the lid of the container up or down. Record the resulting volume and pressure

pH was recorded every time 1.00 mL of NaOH was added to beaker. When the amount of NaOH added to the beaker was about 5.00 mL away from the expected end point, NaOH was added very slowly. Approximately 0.20 mL of NaOH was added until the pH made a jump. The pH was recorded until it reached ~12. This was repeated two more times. The pKa of each trial are determined using the graphs made on excel.

A buffer is a solution that resists changes in pH when H+, OH-, or H20 is added. By using standard lab equipment, a lab pro diagnostic tool, and acidic and basic solutions, the pH can be found. By recording the pH while adding a base or an acid gradually to a buffer solution you can find the capacity of each buffer to resist drastic changes in pH. The best buffers will keep a solution from becoming either too acidic or basic with the addition of a strong base or acid.

6. Select the lab book and click on the data link for Ideal Gas 1. In the Data Viewer window, select all the data by clicking on the Select All button and copy the data using CTRL-C for Windows or CMD-C for Macintosh. Paste the data into a spreadsheet program and create a graph with volume on the x-axis and pressure on the

2A. Evaporation is related to the properties of matter because it is a liquid and a gas. We know this because there are three states of matter which are soild, liquid and gas since evaporation first starts as a liquid (water). Then it turns into gas (cloud).

For this lab, we brought a empty soda can to school to show how pressure and temperature can affect the structure of the can. To begin the experiment, we needed a empty soda can, water and ice in a small plastic tub, and a hot plate. First, we added about a tablespoon of water to the empty soda can. Second, we put the soda can on the hot plate and waited until the water was brought to a boil. Then we used beaker tongs to carry the hot soda can and flipped it over into the container of water and ice. Once the can touched the water, the can made a loud crushing sound and the can crippled inward.

In this experiment, the identity of an unknown compound will be deduced from analysis of physical properties, boiling points, IR spectra, chemical tests, and melting points of derivatives. This experiment allows for individual selection of chemical tests, order of steps, and additional analysis, as necessary, based on what is needed to determine identity of unknown.

b. Place crushed ice in the beaker so the water level is just below the top of the

1. Start Virtual ChemLab and select Boyle’s Law: Pressure and Volume from the list of assignments. The lab will open in the Gases laboratory.

The volume is definite if the temperature and pressure are constant. When a solid is heated above its melting point, it becomes liquid, given that the pressure is higher than the triple point of the substance. Intermolecular (or interatomic or interionic) forces are still important, but the molecules have enough energy to move relative to each other and the structure is mobile. This means that the shape of a liquid is not definite but is determined by its container. The volume is usually greater than that of the corresponding solid, the most well known exception being water, H2O. The highest temperature at which a given liquid can exist is its critical temperature.[5]

The objectives of this lab are, as follows; to understand what occurs at the molecular level when a substance melts; to understand the primary purpose of melting point data; to demonstrate the technique for obtaining the melting point of an organic substance; and to explain the effect of impurities on the melting point of a substance. Through the experimentation of three substances, tetracosane, 1-tetradecanol and a mixture of the two, observations can be made in reference to melting point concerning polarity, molecular weight and purity of the substance. When comparing the two substances, it is evident that heavy molecule weight of tetracosane allowed