CHEM 120 Week 8 Lab Practicum
CHEM 120 Week 8 Lab Practicum 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.
- Question: (CO 1) What was the independent variable in this experiment? (3 points)
- Question: (CO 1) What theory could you produce based off these results? (3 points)
- 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.
- Question: (CO 7) Select all solutions that have a basic pH value. Select all that apply)
- Question: (CO 6) Which of the following solutions do you believe would have the greatest H3O+ concentration? (3 points)
- 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.
- Question: (CO 3) Based on the conductivity results here, select the compounds that would be considered ionic. Select all that apply. (3 points)
- Question: (CO 6) What would be the % concentration of the NaF solution?
- Question: (CO 2) What is the name of the substance MgCl2?
- 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
- 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)
- Question: What is the structural formula for the compound above? (3 points)
- 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.
- 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)
- 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.
- Question: (CO 9) This chunk of material is decaying by electron What is the product of this decay? (3 points)
CHEM 120 Week 8 Lab Practicum Online Quiz
- Question: If a patient has fever of 103 ◦F, convert it in degree Celsius
- Question: You are given 500 mg NaCl. If it is dissolved in 7.5 mL water what would be the density in g/mL?
- Question: Provide name of the following organic compound CH3-NH2
- Question: Provide structural formula of the following organic compound (3 points).
Ethyl amine - Question: You are … a pH meter and a series of solutions (solutions A, B and C). When you … pH, the results were as follows: pH of solution A= 5.0; pH of solution B= 3.5; pH of solution C= 8. Rank the solutions from most acidic to least acidic. (6 points)
- Question: Balance the following reaction (3 points). If the reaction is … out using 8 moles of KHCO3, how many moles of K2SO4 will … produced (3 points)?
H2SO4 + KHCO3 → K2SO4 + CO2 + H2O - Question: Based on given atoms or ions, write names and formulas of the compounds (2 points). Identify the compounds as ionic or covalent A compound made of Barium and phosphate
- Question: Based on given atoms or ions, write names and formulas of the compounds (2 points). Identify the compounds as ionic or covalent (1 point).
CHEM 120 Week 8 Lab Practicum Online Quiz
- Question: You are given the following pH values: Solution 1: 2, Solution 2: 4.8, Solution 3: 12.7, Solution 4: 1.1
- Which solutions are basic?
- Which solution would have the highest concentration of H3O+ ions when dissolved in water?
- Question: You are given three compounds: NaCl, CH3CH2OH (ethanol), and CaCl2. You are asked to measure out 14.7 g of each compound into three separate 500-mL flasks and add enough water to make 500-mL of solution. A chemist comes along and measures the conductivity of each of the solutions and find that both the NaCl and CaCl2 solutions are highly conductive and the ethanol solution isn’t conductive at all. Answer the following
- Using your knowledge of the compound structures, bond types, and conductivity results, which compounds are ionic and which are not?
- Determine the percent concentration of the three
- What are the names of the two ionic compounds used in the experiment?
- Question: You are given the structure of an organic molecule (right):
- What is the name of the compound shown and what is the functional group?
- What is the condensed structure for the compound above?
- What type of bond exists between C and H and between O and H?
- Question: It is an unseasonably warm day in late November where the temperature reached a surprising 80 oF in Vail, CO (elevation 8500 ft). To celebrate, you decide to have your child’s birthday party in the backyard and tape really fancy balloons to your mailbox and front door. The next morning, you forgot that the balloons were left out overnight and the temperature dropped below freezing. Answer the following questions.
- When you go out to retrieve your balloons, what do you expect to see?
- What do you think could happen if you filled a balloon to the bursting point in the city of Denver and drove it to Vail, CO?
- Question: Chromium-51 (51Cr) has a half-life of 30 days and decays by electron Answer the following questions.
- What is the decay product of 51Cr?
- If you had 100 g of Cr-51 initially, how many grams would you have after 90 days?
- Question: Balance the following chemical reaction: Ca3(PO4)2 + MgO ==> CaO + Mg3(PO4)2
