Microorganisms are found throughout the environment: in the air and water; on the surface of any object such as clothes, walls, furniture; in soil and dust; and on and in our own bodies skin and mucous membranes. The first curve plots time versus temperature of pure naphthalene; the second curve plots time versus temperature of a solution of sulfur in naphthalene. Start Virtual ChemLab and select Boiling Point Elevation from the list of assignments. The temperature reading from the thermometer was recorded every 30 seconds. Unfortunately these cooling curves are not available online.
Students will fill out the lab worksheet which will help guide them in the lab. The freezing point of salt water is lower than the freezing point of fresh water. In this lab report, we will discuss: 1. Such properties are called colligative properties. Carbon dioxide, Cell nucleus, Eukaryote 1091 Words 4 Pages platform it shows why it is harder to drive on some surfaces then others.
Osmosis is the diffusion of the movement of water from a region of higher concentration to a region of lower concentration through a cell membrane or other semi-permeable membrane until an equilibrium is reached. Caffeine, Coffee, Embryo 700 Words 3 Pages lab reports becca Medina Biology Lab 1107 Lab Notebook The Scientific Method Problem: Will a male or female have a higher heart rate after participating in the physical activity of running up three floors of a building? The salt water had a lower freezing point than the pure water by 2 degrees which supports the hypothesis that solutions. Record the mass in Data Table A. The solution has an osmotic pressure of 8. Record your preditions and observations in the Data an Observations section of your labatory report format. The molal freezing-point constant used is the constant for the solvent, not the solute.
Of these three, osmotic pressure is the most sensitive and gives the best results. Some information has been provided for you, but still needs to be included on your slides. Two ice baths were made, one with pure water, the other with salt water. An example of freezing point depression is when one adds anti-freeze to car fuel to prevent the fuel from freezing in cold temperatures, like we are experiencing in the north east region now. The glass jar was also emptied into the sink and rinsed thoroughly. Temperature Readings for Freezing Point.
Make sure the thermometer is not resting or touching the sides of the test tube. Qu estions - Part 2 To what biological structure is the dialysis bag comparable? Once, the temperature was consistent, the test tube was removed from the ice water bath, and emptied in the sink. The white charge producer has a positive + polarity. Materials and Methods: I placed ten drops of each substance into different wells. In the results of the experiment, the molar mass was found to be 192.
Hydrogen peroxide decomposes in the presences of light or heat. Basic Explanation : Osmosis can occur when there is a partially permeable membrane. There are up to nine pressure tappings as shown in Fig 1. It is customary to express this tendency toward solvent transport in pressure units relative to the pure solvent. Each Friday I will ask to see your completed prelab before I allow you to enter the lab. The lab report consists of three sections: Data, Exploration, and Lab Summary.
The experimenter should become familiar with basic operations necessary. Problem: How can matter and energy be described in. Time seconds Temp °C of control tap water Temp °C of solution + 0. That, plus the fact that all the starting and finishing materials are non hazardous and safe, is why this is one of the first chemical reactions that many people are exposed to The purpose of this experiment tests which of the two reactants vinegar and baking soda is the limited. Then I took Magnesium and put it in the first one.
It is customary to express this tendency toward solvent transport in pressure units relative to the pure solvent. Record the mass of the sodium chloride in the data table. To what biological structure is the dialysis bag comparable? After the shell dissolved completely in the vinegar, the egg was carefully removed from the jar, and rinsed with cool tap water. Each section must be present in a complete report. By: Jordan Hribar 1034044 Partner: Anthony Cuillierier Teacher: Daniel Baril Experiment Done: February 23rd, 2011 Experiment Number 2. The bowl was emptied in the sink, rinsed with distilled water, and then filled half way again with more distilled water.
Which of the following is true of osmosis? Over the hours, the membrane shape was oval but looked to be getting flatted almost as if someone pressed it together from the top and bottom. The lowest temperature was then record for each bath and compared. You may type them in this word document, then print it out and bring it to lab. Hypothesis: If the radish seeds put in the dish with the drink Monster, then the seeds will grow faster because of the amount of energy given to them. Historically certain colligative properties — freezing point depression, boiling point elevation, and osmotic pressure — have been used to determine molecular mass. For this reason we hypothesized that.
The substance would seem lighter than it is. This solution was mixed well until all the salt was dissolved. Once all data was recorded, the egg was thrown away in the trash and the syrup was rinsed down the sink. Earth's gravity, Force, Gram 1023 Words 5 Pages Using Freezing-Point Depression to Find Molecular Weight Abstract: In this lab, the purpose was to use the freezing point depression method to determine the molecular weight of aspirin. If too much was used it could affect the results. The second goal of the experiment is to teach students about osmosis. An example of vapor pressure lowering would be freeze drying.