SCIN 131

SCIN 131 Tests and Quizzes 6 Part 1 of 1 - 100.0 Points Question 1 of 25 4.0 Points `Suppose you have a fixed container containing 2.48 moles of gas. If the container volume is 30.0 L, and the pressure is 2.05 atm, what is the temperature (°C)? (R= 0.0821 L ∙ atm / mol ∙ K) A.302 B.-84 C.189 D.29 Answer Key: D Feedback: Ideal gas law is discussed in 11.8 Question 2 of 25 4.0 Points `I have a pressure cooker in my underground lair that is brewing a diabolical solution. I set everything up and went upstairs, but forgot to write down the initial temperature. When I came downstairs later to check on it, I see that the pressure gauge shows that the pressure has decreased by 10 times, while the volume increased by 5 times. The temperature now reads -123.15 °C. What was the starting temperature when I left (in °C)? A.-198 B.75 C.27 D.300 Answer Key: C Feedback: Good. Combined gas law is discussed in 11.6 Question 3 of 25 4.0 Points `Which sentence below is NOT true about pressure? A. After creating a pressure difference, the atmospheric pressure can push liquid up a straw. B. The atmosphere has a pressure as the components of air collide with surfaces. C.A deep well dug in the ground must have the pump located at the bottom of well in order to have the water come to the surface. D.Pressure is caused by gas molecules colliding with surfaces. E.All of the above statements are true. Answer Key: E Feedback: Good. pressure is discussed in 11.3 Question 4 of 25 4.0 Points `I have a cylinder sitting in my lab that contains 0.500 L of 25.85 C gas, and it's pressure is 14.7 psi. If I push the cylinder and increase the pressure to 22.6 psi and the temperature to 59.85 C, what will be the new volume of the gas in L? A.2.77 L B.0.691 L C.0.362 L D.1.45 L Answer Key: C Feedback: Good. Combined gas law is discussed in 11.6 Question 5 of 25 4.0 Points `I am blowing up balloons for my daughter's birthday party. I want them to float while tethered to a table, but I only have a little bit of helium left in the tank. So I can only use a little in each balloon, and I will fill the rest of the balloon with oxygen and nitrogen (I thought it would be much more entertaining to have elemental oxygen in the balloons around all those birthday candles!). Suppose that in each balloon, the oxygen has a pressure of 0.292 atm and the nitrogen has a pressure of 0.587 atm. If the total pressure inside the cylinder is 1.01 atm, what is the pressure that is due to the helium? A.0.131 atm B.1.01 atm C.0.879 atm D.0.722 atm Answer Key: A Feedback: Good. Partial pressures are discussed in 11.9 Question 6 of 25 4.0 Points `Given the conversion factors and definitions discussed in the lesson, which of the following is equivalent to 2 atm? A. 1,520 torr. B. 1,520 mm Hg. C.29.4 psi. D.202,650 Pa. E.all of these choices Answer Key: E Feedback: Good. Gas law conversions are discussed in section 11.3 Question 7 of 25 4.0 Points `The air that we breathe is actually a mixture of several gases. Of those involved, which is the major component of the mixture? A.carbon dioxide B.nitrogen C.smog D.oxygen E.argon Answer Key: B Feedback: Good. Gas mixtures are discussed in 11.9 Question 8 of 25 4.0 Points `Suppose you have a fixed container containing 0.255 moles of a gas (the identity of the gas doesn't matter). If the container volume is 0.748 L, and the temperature is 301.15 K, what is the pressure in atm? (R= 0.0821 L ∙ atm / mol ∙ K) A.8.42 atm B.0.784 atm C.7.84 × 10-4 atm D.0.00842 atm Answer Key: A Feedback: Good. Ideal gas law is discussed in 11.8 Question 9 of 25 4.0 Points `The air that we breathe is actually a mixture of several gases. Of those involved, which is the third most abundant component of the mixture? A.nitrogen B.carbon dioxide C.smog D.oxygen E.argon Answer Key: E Feedback: Good. Mixtures of gases are discussed in 11.9 Question 10 of 25 4.0 Points `Think about the combined gas law. If you start with a pressure of 1.00 atm, but the volume is cut in half while the temperature triples, what is the resulting pressure? A.2.00 atm B.1.50 atm C.0.667 atm D.6.00 atm E.not enough information Answer Key: D Feedback: Good. The combined gas law is in 11.6 Question 11 of 25 4.0 Points `You have been given a 200.00 mL canister containing an unidentified gas. After accounting for the mass of the container, you determine the mass of the actual gas is 0.376 g. The pressure gauge on the cannister reads 874 mmHg, and the temperature gauge reads 298.15 K. What is the identity of the gas? (R= 0.0821 L atm/ mol K) A.He B.Ne C.Ar D.Kr E.not enough information Answer Key: C Feedback: Good. PV=nRT is in section 11.8 Question 12 of 25 4.0 Points `I have a cylinder sitting in my lab that contains 0.7500 L of gas, and it's pressure is 16.24 psi. If I relieve the cylinder and change the pressure to 6.961 psi, what will be the new volume of the gas in L? A.1.750 L B.3.151 L C.321.4 mL D.630.0 mL Answer Key: A Feedback: Good. Boyle's law is discussed in 11.4 Question 13 of 25 4.0 Points `I recently visited the Children's Museum with my kids, and they had a really awesome display about pirates, sunken ships, and artifacts and treasure that had been salvaged from shipwrecks. When they bring these pieces to shore, like the canons, they do so by attaching balloons to them that are inflated under water, and they simply lift the artificats to the surface. If one of those balloons contains 3.00 L of air that has a pressure of 36.74 psi, what is the gas volume (the volume of the balloon) once it floats to the surface? A.5.50 L B.7.50 L C.0.833 L D.1.20 L Answer Key: B Feedback: Good. This is Boyle's law, section 11.4 Question 14 of 25 4.0 Points `My kids love balloons. It's weird, really. If one of their He balloons contained exactly 1 mol of He, and I also gave them a balloon containing exactly 1 mol of oxygen gas (I know, great parenting, right?), and the atmospheric conditions were equal to standard temperature and pressure (STP), which of these statements about the balloons is true? A. Their volumes will be the same. B. Their masses will be equal. C. Their volumes AND their masses will be equal. D. Neither their volumes NOR their masses will be equal. E. not enough information to answer this question Answer Key: A Feedback: Good. Remember volume at STP as discussed in section 11.10 Question 15 of 25 4.0 Points `My kids love balloons. It's weird, really. So I am no stranger to seeing one miraculously get unattached from them and float away in the sky. If one of their balloons floated so high that it reached an area where the pressure and temperature of the atmosphere BOTH decreased proportionally to one another, what would the balloon look like at that point compared to when it initially left the ground? Assume no gas molecules leaked out of the balloon during this process. (the statements in bold must be considered as part of the answer) HINT: proportionally means, for example, if one doubled in value, so did the other, or if one halved, so did the other, etc. A. Its volume would decrease due to both the temperature and pressure changes. B. Its volume would increase due to the temperature change. C. Its volume would decrease due to both the pressure change. D. It's volume would increase due to both the temperature and pressure changes. E. its volume would remain unchanged--it would look like it did when it first left the ground Answer Key: E Feedback: Good. Combined gas law is in 11.6 Question 16 of 25 4.0 Points `Suppose you have a fixed container containing 18.0 g of He gas. If the container volume is 3.00 L, and the temperature is 298.15 K, what is the pressure in atm? (R= 0.0821 L ∙ atm / mol ∙ K) A.36.7 atm B.32.6 atm C.1.81 atm D.147 atm Answer Key: A Feedback: Good.The ideal gas law is discussed in 11.8 Question 17 of 25 4.0 Points `I have a test balloon sitting in my underground lair that contains 500 mL of 298.15 °K gas. If I heat the gas in the balloon to 323.15 °K with my laser gun, what will be the new volume of the gas in L? A.0.542 L B.0.193 L C.0.461 L D.1.00 L Answer Key: A Feedback: Good. Charles' law is discussed in 11.5 Question 18 of 25 4.0 Points `Given the conversion factors and definitions discussed in the lesson, which of the following is equivalent to 2 torr? A.29.4 psi. B.2 Pa. C.1,520 mm Hg. D.2 mm Hg. E.all of the above Answer Key: D Feedback: Good. This is discussed in section 11.3 Question 19 of 25 4.0 Points `Suppose you have a fixed container containing 19.08 grams of one of the diatomic (elemental) gases. If the container volume is 3.82 L, and the pressure is 4.78 atm, and the temperature is 100°C, which gas is it? (R= 0.0821 L ∙ atm / mol ∙ K) A.Br2 B.O2 C.H2 D.F2 E.not enough information. Answer Key: B Feedback: Ideal gas law is discussed in 11.8 Question 20 of 25 4.0 Points `We learned about standard temperature and pressure in this lesson (STP). Which of the following reflect the values of STP? A.298 K, 1 atm B.25°C, 14.7 psi C.273 K, 1 Pa D.273 K, 760 mm Hg E.373 K, 760 torr F.Stone Temple Pilots Answer Key: D Feedback: STP is discussed in 11.10 Question 21 of 25 4.0 Points `If you know the mass, volume, temperature, and pressure of a gas, you can determine it's identity. For example, assuming conditions of standard temperature and pressue, if you have a sample of a noble gas that weighs 12.69 g, in a container with a volume of 14.09 L, which noble gas is it? (R= 0.0821 L atm/ mol K) A.Ar B.Ne C.Kr D.He E.not enough information Answer Key: B Feedback: Good. This uses the ideal gas law from section 11.8 Question 22 of 25 4.0 Points `We've all blown up balloons. When you blow into a balloon, you are putting in more moles of gas. Let's say that on the second exhalation (blow) you blow in the exact same number of moles as you did with the first exhalation. So, you doubled the number of moles in the balloon. If the temperature and pressure remained constant, what is true about the volume of the gas in the balloon? A. The volume increases, but more information is needed. B. The volume is halved. C. The volume decreases, but more information is needed. D. The volume doubles. E. none of the above Answer Key: D Feedback: Good. Avogadro's law is in 11.7 Question 23 of 25 4.0 Points `Suppose you have a helium balloon that is holding 2.00 L of He at a pressure of 15.18 psi. If it's temperature started out as 310.15 K, but was heated to 331.15 K, resulting in an expansion of volume to 3.24 L, what is the final pressure in atm? A.0.681 B.3.21 C.1.79 D.517 Answer Key: A Feedback: Combined gas law is discussed in 11.6 Question 24 of 25 4.0 Points `The Kinetic Molecular Theory (KMT) is discussed in this lesson, and it helps us understand the behavior of gases. From what we learned, which of these statements are consistent with KMT? A. Due to the large amount of empty space between gas molecules/atoms, the density of a gas is very low. B. Gas molecules are in constant, random motion, so they take the shape and volume of whatever container they are in. C.Since atoms are mostly empty space, gases can be compressed. D.Gas molecules/atoms collide with each other and surfaces without losing energy. E.All of the above statements are consistent with KMT. Answer Key: E Feedback: Good. KMT is discussed in 11.2 Question 25 of 25 4.0 Points `I have a pressure cooker in my underground lair that is brewing a diabolical solution. I set everything up and went upstairs, but forgot to write down the initial temperature. I know the starting volume was 1.00 L. When I came downstairs later to check on it, I see that the volume increased to 1.10 L, and thermometer read that the temperature was now 528.15 K. What was the starting temperature when I left (in °C)? A.-41°C B.207°C C.232°C D.480°C Answer Key: B Feedback: Good. Charles' law is in section 11.5