Results: Zinc Metal - Iodine - Iodide + Triodide + Zinc Ion + Focus Questions: 1. Is there a way to put energy into Zinc Iodide in order to regain the elements, zinc and iodine? If there is a way, how does it happen? Yes, this can be done through electrolysis using a battery and exposed wire tips. Take sample of Zinc Iodide and dissolve in solution.
B. The electrons flow from the zinc electrode to the chromium electrode. C. The electrons flow from the chromium electrode to the zinc electrode. D. Zinc is reduced in the reaction. _____ 15.
Dr Khounsary explains an experiment using a fixed voltage and varying the temperature of the wire using a torch. The article further explains that the temperature coefficient of copper at 20 degrees C is .00393 and that a single degree of temperature change would increase the resistance of the wire by that amount. In the article regarding the Effect of Temperature on Conductivity (The Nuffield Foundation, 2006) the article describes how the conductivity of a wire decreases as it is heated. It provides an example schematic diagram for the test circuit and the use of Eureka wire instead of copper wire. A2a.
Coal hypothesis = If I add activated carbon to the water it will lower the pH level of the water. 2. 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. a. Pyrite hypothesis accept/reject = Based on the results of the experiment I would accept the hypothesis on pyrite.
Background: A reaction rate is the decrease in concentration of a reactant or the increase in concentration of a product with time. Thus, the units for the reaction rate are usually Molarity per second (M/s) – that is , the change in concentration (measured in molarity) divided by a time interval (seconds in this case) (Chemistry: The Central Science, P. 527). Rate is usually calculated by taking an average of the disappearance or appearance of a compound with respect to time. In this case it is calculated by the absorbance of the light. Reaction rate is affected by any catalysts present (which speed up the reaction usually with an intermediate step), temperature (increases the number of particles collisions), concentration (increases the number of collisions), and surface area (increases the space available for collisions).
Explain the effect that the flow tube radius change had on flow rate. How well did the results compare with your prediction? The increase of flow tube radius increased the flow rate, as predicted. 3. Describe the effect that radius changes have on the laminar flow of a fluid.
Percent Copper and Formula Weight of a Copper Compound Introduction: In many chemistry problems, you are asked to calculate the percent composition of each element in a compound. In this experiment a variation of this basic calculation will be employed. The amount of copper in a compound will be determined by dissolving the unknown compound in water. The copper ions in solution will be converted to metallic copper by reaction with magnesium metal. To ensure that all of the copper is removed from solution, an excess of magnesium will be used.
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 (24-48 hours) | |Pyrite |5 |6 | |Activated Carbon |6 |7 | |Water |5 |5 | POST LAB QUESTIONS 1. Develop hypotheses predicting the effect of pyrite and coal on the acidity of water? a. Pyrite hypothesis = Pyrite will contaminate the water source making it more acidic. b. Coal hypothesis = Coal will contaminate the water source making it more acidic.
Once more alkali is added to this, the solution will begin to increase again in pH, going up to 12 – 14, and being blue/purple in colour through testing with indicator. This would be because there would then be more OH- ions. Hypothesis and prediction: Concentration of an acid affects the pH during a titration. As the concentration of the acid increases, I predict that the volume of alkali needed to change the pH to reach an end point will also increase. I also predict that doubling the concentration of acid will require double the amount of alkali to reach an end point.
A. The reduction of the final electron acceptor: NADP B. Plastocyanin picking up and transferring electrons across the membrane C. The splitting of water to replace the electron in the reaction centre chlorophyll D. Through photophosphorylation (12) Which of the following is false? A. Plastocyanin is a non-lipophilic electron carrier, whereas plastoquinone is a lipophilic