This is just a study guide to help you think about the concepts we covered in this unit, but study guides do not always cover or review everything. Here's some things you can do to prepare for the Unit 3 Exam:
1) Make sure you can explain each of your answers to this Problem Set. Do you understand the concept or did you just memorize arithmetic?
2) Review your Concentration of Dye in Gatorade lab
3) Review your notes. We covered the following topics this unit:
Molarity and Dilutions
Photoelectric Effect (energy, wavelength, frequency) concepts and calculations
Spectroscopy (how do molecules interact with different types of radiations/light)
Beer-Lambert Law
Ideal Gas Law (variable relationships and calculations)
Partial Pressure
Kinetic Molecular Theory (KMT)
Deviation from the Ideal Gas Law
The hardest part of AP exams is that you have to think flexibly. If you truly understand a topic, you can answer a question no matter how it is presented.
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1.
How many milliliters of 18.2 M H2SO4 are needed to prepare 600.0 mL of 0.10 M H2SO4?
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2.
What volume of a 0.100M HCl stock solution should be used to prepare 250.00mL of 0.0250M HCl?
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3.
Which of the following frequencies corresponds to light with the longest wavelength?
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4.
What is the wavelength of a photon of red light whose frequency is 4.55 × 1014 Hz?
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5.
Yellow light can have a wavelength of 5.99x10-7 nm. The energy of a photon of this light is _______ .
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6.
Food can be heated in a microwave oven when microwave radiation strikes water molecules. Which statement best describes what happens to a water molecule when it is struck by microwave radiation?
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7.
Carbon dioxide, CO2, is capable of absorbing infrared (IR) radiation and is consider a greenhouse gas. Which statement correctly describes what happens when CO2 absorbs IR radiation?
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8.
Which of the following best explains what happens as photons of visible light are absorbed by dye molecules?
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9.
The absorption spectrum of a certain red dye is shown above. If a student analyzing the same concentration of this dye neglected to wipe fingerprints off the cuvette before placing it in the spectrophotometer, how would the absorption curve be affected?
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10.
An experiment was performed to investigate the reaction between Zn metal and Ni2+ (aq) at different concentrations. Because the Ni2+ (aq) ion is green, the extent of the reaction was determined using spectrophotometric analysis. Four 20.0mL standard solutions of Ni2+ (aq) were prepared by dissolving NiCl2⋅6 H2O (molar mass 240g/mol) in water. The absorbance of each solution was measured; the results are shown both in the table below and in the following plot of the absorbance data.
What is the expected absorbance of a standard solution made by dissolving 0.0070 mol of NiCl2⋅6H2O in water to make 100.mL of solution?
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11.
A gaseous air‑fuel mixture in a sealed car engine cylinder has an initial volume of 600 mL at 1.0 atm. To prepare for ignition of the fuel, a piston moves within the cylinder, reducing the volume of the air‑fuel mixture to 50 mL at constant temperature. Assuming ideal behavior, what is the new pressure of the air‑fuel mixture?
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12.
At 10.°C, 20.g of oxygen gas exerts a pressure of 2.1atm in a rigid, 7.0L cylinder. Assuming ideal behavior, if the temperature of the gas was raised to 40.°C, which statement indicates the new pressure and explains why?
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13.
You fill a balloon with 2.50 moles of gas at 22°C at a pressure of 1.19 atm. What is the volume of the balloon?
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14.
A gaseous mixture containing 1.5 mol Ar and 3.5 mol CO2 has a total pressure of 8.6 atm. What is the partial pressure of CO2?
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15.
Two sealed, rigid 5.0L containers each contain a gas at the same temperature but at a different pressure, as shown above. Also shown are the results of transferring the entire contents of container 1 to container 2. No gases escape during the transfer. Assuming ideal behavior, which statement is correct regarding the total pressure of the gases after they are combined?
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16.
The partial pressures of CH4, N2, and O2 in a sample of gas were found to be 187 mmHg, 487 mmHg, and 555 mmHg, respectively. Calculate the mole fraction of nitrogen.
Note: mmHg (millimeter of mercury) is a unit of pressure. When working with partial pressure problems, the unit of pressure does not need to be in atmospheres (atm).
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17.
Four identical 1.0-L flasks contain the gases He, Cl2, CH4, and NH3, each at 0°C and 1 atm pressure. For which gas do the molecules have the highest average particle speed?
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18.
The diagrams above use arrows to represent the speed of a gas particle. Which of the diagrams best represents the speed of the particles of a gas at a fixed temperature, and why?
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19.
Of the four gases below, which gas would have the largest deviation from ideal behavior?
Note: Attractive forces are more of a factor than volume.
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20.
The diagrams above represent two samples of Xe gas in containers of equal volume at 280K. Which of the following correctly compares the two samples in terms of their deviation from ideal gas behavior and explains why?
