Lab 4 – Energy Sources and Alternative Energy Experiment 1: The Effects of Coal Mining |Water Sample |Initial pH |Final pH (24-48 hours) | |Pyrite |7 |4 | |Activated Carbon |7 |8 | |Water |7 |7 | POST LAB QUESTIONS Develop hypotheses predicting the effect of pyrite and coal on the acidity of water? Pyrite hypothesis = If the pyrite is left in a warm climate in water for 48 hrs, then it will have a higher pH then the initial Coal hypothesis = If the Coal is left in a warm climate in water for 48 hrs, then it will have a lower pH then the initial Based on the results of your experiment, would you reject or accept each hypothesis that you produced in question 1? Explain how you determined this. Pyrite hypothesis accept/reject = Reject. According to the pH balance strips, my pyrite recorded a significantly lower pH of 4.
Lab 4 – Energy Sources and Alternative Energy Experiment 1: The Effects of Coal Mining |Table 1: pH of Water Samples | |Water Sample |Initial pH |Final pH (after 48 hours) | |Pyrite |6 |6 | |Activated Carbon |6 |7 | |Water |6 |6 | POST LAB QUESTIONS 1. Develop hypotheses predicting the effect of pyrite and coal (activated carbon) on the acidity of water? a. Pyrite hypothesis = The pyrite will probably dissolve a bit and increase the ph of the water b. Coal (activated carbon) hypothesis = The activated carbon will probably increase the ph of the water as it dissolves and releases chemicals into the water 2. Based on the results of your experiment, would you reject or accept each hypothesis that you produced in question 1?
Determination of Freezing Point and Verification of Freezing Point Depression for a Mixture by Linah Richer Partners: Maike Blakely CHM317 Preformed: Nov. 8th, 2013 Report: Nov. 19th, 2013 Abstract: The purpose of this experiment is to determine the freezing point of the solvent, biphenyl, and verify the freezing point depression equation ΔTf=-ikfnsolutemsolvent. The addition of solute will lower the vapor pressure of the solvent/solute mixture resulting in the lowering of the freezing point for the mixture solution. The experiment resulted in the experimental difference in the two trial freezing points to be 0.08 K leading to a calculated change in temperature freezing to be -1.92 E -5 K, and an overall decrease in temperature freezing of the solute/solvent solution compared to the pure solvent solution. Introduction: Experimentally it is understood that the addition of a nonvolatile solute to a solvent will lower the vapor pressure, raise the boiling point and lower the freezing point. In this experiment, the freezing point for the solvent biphenyl will be determined theoretically and experimentally, as well as the verification of the freezing point depression equation for a solvent/solute mixture.
The mixture was refluxed to avoid evaporation while it boiled for 30 minutes. After 30 minutes the mixture was cooled and then filtered through fluted filter paper into a 250ml round bottom flask. The methyene chloride dissolved the trimystrin and would pass through the filter paper leaving the other nutmeg solids behind. The solution was then distilled to get rid of the methlyene chloride and isolate the trimyristin. Methlyene chloride was a good solvent in this case because its boiling point is 40 degrees C and will boil off before the trimyristin which has a boiling point of 56-57 degrees C. Finally acetone was added to wash the crystals and the solution was vacuum filtered.
2: First you measure the mass of the copper tacks and also try to get the mass of the water in the thermos as close to 0.1 kg since 1 dl of H20 = 0.1kg H20. 3: Using the test tube holder, sink the test tube with the copper in it into the 4: The electric kettle is now supposed to make the water boil and raise the temperature of the copper as close to 100ºC (T1cu) but it is not very likely that you will get exact 100ºC due to heat loss. This step will almost certainly take a couple of minutes. 4: Measure the temperature of the water in the thermos (T1w) and then add the tacks to the water in the thermos. 5: Now measure the temperature of the water (T2cu and T2w will have the same temperature).
The loss in mass has taken place as the sucrose concentration has a low water potential, consequently the water leaves the potato tissue as it has a higher water concentration, thus the potato tissue loses mass. However, after 0.8M, we can see that the graph starts to curve off. If we were to add a few more concentrations of sucrose then we would see that there would be no further water loss. This would indicate that the potato tissue has become fully plasmolysed. I believe the results
This leads to the question how acidic will the oceans become and what affect will this have on creatures that live within them? The surface of the ocean has a lower concentration of carbon dioxide than the atmosphere which causes it to act like a sponge soaking up the carbon from the air. Roberts goes on to say how over two hundred years the ocean as a whole has only lowered in pH by 0.1 of a unit. This may not sound like much but the author explains that the pH scale is logarithmic, which means that sea water is now actually 30% more acidic than two hundred years ago at the start of the Industrial Revolution. The author gives an example that acidifying the ocean is a similar chemical process much like producing carbonated drinks, except the ocean doesn’t become fizzy.
An acid is a chemical compound that dissociates in a solution and releases hydrogen ions which lowers the pH. A base is the opposite so it donates hydrogen ions making the pH rise. A compound that neutralizes both acids and bases when added to a solution is referred to as a buffer. This is all tied together by the process of titration, which determines the concentration in a solution by adding to it a substance of known concentration in specific amounts. Before testing this experiment, I expected the pH to increase when the acid was added and to decrease when the base was added.
The fuel is what’s being oxidized. For example a burning log is undergoing pyrolysis and is turning into a vapor. The process of turning a liquid into a gas is called vaporization and is the same concept as pyrolysis, except it generally requires less heat. An example of that is water left out in room temperature will slowly evaporate, where a piece of wood will not. The next theory is the fire tetrahedron.
1.1 Title: Investigating Viscosity 1.2 Research Question: How does varying the temperature (15 C, 30 C, 45 C, 60 C, 75 C) of 300cm^3 of cooking oil affect its viscosity, calculated by measuring the average velocity of a steel ball weight of 5g, falling through a 300cm^3 glass tube (25 cm in length)? 1.3 Scientific background: The intermolecular forces between the liquid molecules affect the viscosity of a liquid. As temperature increases, the intermolecular forces are weakening and some of them are overcome. Thus, the viscosity of cooking oil will decrease with an increase in temperature. As the liquid is more viscous, the ball weight would be experiencing more resistance in its motion and would thus have a lower average velocity.