CHEM 120 Week 8 Lab Practical Online Quiz

Station 1. You have run an experiment studying the effects of the molecular weight of a compound on the rate of diffusion in agar. Compound X has a molecular weight of 25.3 g/mol and compound Y has a molecular mass of 156.2 g/mol. On two separate agar plates, 0.1 g of each substance were transferred and allowed to diffuse for 2 hours. The results below were obtained. Use this information about this situation to answer the following three questions. 1. Question: (CO 1) What was the independent variable in this experiment? (3 points) 2. Question: (CO 1) What theory could you produce based off these results? (3 points) 3. Question: (CO 1) List two controls that were held constant for this experiment or that you would hold constant for this experiment. (4 points, 2 points each). Station 2: You measure the pH of a series of solutions using a pH meter using a pH meter and receive the following results. Use these results to answer the following three questions below. 4. Question: (CO 7) Select all solutions that have a basic pH value. Select all that apply) 5. Question: (CO 6) Which of the following solutions do you believe would have the greatest H3O+ concentration? (3 points) 6. Question: (CO 7) One of these solutions contains a strong acid. Which of these compounds would you expect this is? (3 points) Station 3: You pace 4.6 grams of each of the following substances in the bottom of 3 separate beakers: NaF, CH3OH, and MgCl2. You then add water to each beaker such that each beaker has a volume of 500 ml. You then stir these solutions and collect the data below. Use this experiment and data to answer the next four questions. 7. Question: (CO 3) Based on the conductivity results here, select the compounds that would be considered ionic. Select all that apply. (3 points) 8. Question: (CO 6) What would be the % concentration of the NaF solution? 9. Question: (CO 2) What is the name of the substance MgCl2? 10. Question: (CO 1) When dissolved in solution, NaF will separate to produce Na+ ions and F- ions. How many electrons will be in the F- ion? Station 4 11. Question: (CO 8) Give BOTH the name of the functional group in the organic molecule as well as the name of the organic molecule? (1 point for group, 2 points for name) 12. Question: What is the structural formula for the compound above? (3 points) 13. Question: (CO 3) Based on the structure above, what would be the best way to describe the bond between the O and the H? (3 points) Station 5: You pump gas into a balloon until it has a volume of 5.4 Liters when you are holding this balloon in a room with a pressure of 1 ATM in a room with a temperature of 24 degrees Celsius. You take this balloon and subject it to different conditions. Use this information to answer the two questions below. 14. Question: You move the balloon to an adjacent room where the temperature is about 31 degrees Celsius. Assume that the temperature is the only variable changing. You would expect: (3 points) 15. Question: You place the balloon a few meters underwater where the pressure is 1.2 ATM underwater (assume no change in temperature). You would expect: (3 points) Station 6: You have a chunk of radioactive iron with a mass number of 55 (Fe-55). This isotope has a half life of about 2.5 years. Use this information to approach the next two questions. 16. Question: (CO 9) This chunk of material is decaying by electron capture. What is the product of this decay? (3 points) 17. Question: (CO 9) What % of this sample will remain after 5 years. (3 points) Station 7 18. Question: (CO 4) You react chemicals in a flask and observe the reaction below. Balance this chemical Equation. Mg3P2 + CaS → MgS + Ca3P2. (3 points)