Q&A Hero

Q: Zn(s) + 2HCl(aq) -> H2(g) + ZnCl2(aq)When 25.0 g of Zn reacts, how many L of H2 gas are formed at STP?A) 4.28 LB) 0.0171 LC) 8.56 LD) 22.4 LE) 0.382 L

Q: What is the mass of neon that exerts a pressure of 720. mmHg,with a temperature of -15.0 C , when the volume of the container is 760. mL? A) 0.0340 g B) 0.686 g C) 0.615 g D) 517 g E) 25.8 g

Q: What is the pressure, in mmHg, of a 4.00 g sample of O2 gas, which has a temperature of 30.0 C, and a volume of 3000 mL? A) 0.788 mmHg B) 1.04 mmHg C) 78.0 mmHg D) 7880 mmHg E) 788 mmHg

Q: What is the mass of a sample of O2 gas, which has a pressure of 740.mmHg, at a temperature of 25 C, in a volume of 250. mL? A) 0.318 g B) 3.82 g C) 201 g D) 292 g E) 320. g

Q: What volume would a 0.250 mole sample of H2 gas occupy, if it had a which has a pressure of 1.70 atm, and a temperature of 35 C? A) 0.269 L B) 0.423 L C) 1.25 L D) 3.72 L E) 283 L

Q: The mathematical expression of the ideal gas law is A) P1V1 = P2V2. B) = . C) = . D) PV = nRT. E) PT = P1 + P2 + P3.

Q: At STP, what is the volume of 1.00 mole of carbon dioxide? A) 1.00 L B) 44.0 L C) 273 L D) 22.4 L E) 12.2 L

Q: At STP conditions, 11 g of SO2 has a volume of A) 250 L. B) 3.8 L. C) 22 L. D) 0.0076 L. E) 130 L.

Q: The pressure exerted by a gas on its container is directly proportional to A) the volume of the container. B) the mass of the individual gas molecules. C) the centigrade temperature of the gas. D) the number of moles of gas in the sample. E) the Fahrenheit temperature of the gas.

Q: How many moles of neon occupy a volume of 14.3 L at STP? A) 36.7 moles B) 32.0 moles C) 6.45 moles D) 0.638 moles E) 1.57 moles

Q: At STP, temperature and pressure have the values of A) 0 K and 1 atm. B) 273 K and 1 mmHg. C) 273 K and 760 mmHg. D) 0 K and 760 mmHg. E) 760 K and 273 atm.

Q: According to Avogadro's law A) the volume of a gas is inversely related to the number of moles at constant temperature and pressure. B) the volume of a gas is inversely related to the number of moles at standard temperature and pressure. C) the volume of a gas depends only on the temperature and pressure. D) the volume of a gas depends only on the number of moles in the sample. E) the volume of a gas is directly related to the number of moles at constant temperature and pressure.

Q: At STP, what is the mass of 11.2 liters of O2 gas? A) 16.0 g B) 32.0 g C) 64.0 g D) 128 g E) 8.00 g

Q: At STP, how many moles of helium gas would occupy 1.00 L? A) 2.24 moles B) 224 moles C) 22.4 moles D) 0.446 moles E) 0.0446 moles

Q: At STP, what is the volume of 4.50 moles of nitrogen gas? A) 167 L B) 3420 L C) 101 L D) 60.7 L E) 1230 L

Q: A sample of nitrogen gas had a volume of 500. mL, a pressure in its closed container of 740 torr, and a temperature of 25 C. What was the new volume of the gas when the temperature was changed to 50 C and the new pressure was 760 torr, if the moles are constant? A) 530 mL B) 450 mL C) 970 mL D) 240 mL E) 400 mL

Q: A diver exhales a bubble with a volume of 250 mL at a pressure of 2.4 atm and a temperature of 15 C. What is the volume of the bubble when it reaches the surface where the pressure is 1.0 atm and the temperature is 27 C, if the moles are constant? A) 580 mL B) 630 mL C) 100 mL D) 110 mL E) 1100 mL

Q: At 570. mm Hg and 25 C, a gas sample has a volume of 2270 mL. What is the final pressure (in mmHg) at a volume of 1250 mL and a temperature of 175 C, if the moles are constant? A) 1560 mmHg B) 210. mmHg C) 700. mmHg D) 690. mmHg E) 470. mmHg

Q: When the combined gas law is rearranged to solve for V2, the following is the correct expression: V2 = A) T2T1V1/P2P1. B) P1V1T2/P2T1. C) P1V1T1/P2T2. D) P2T2/P1V1T1. E) P1V1/T1 - P2/T2.

Q: An autoclave is used to sterilize surgical equipment because A) it allows water to boil at temperatures less than 100 C. B) it allows water to boil at 100 C at pressures less than 1 atm. C) it allows water to boil at 100 C at pressures greater than 1 atm. D) it allows water to boil at temperatures above 100 C. E) it provides very high temperatures and very low pressures.

Q: Vapor pressure can be described as A) the temperature at which bubbles of vapor appear in a liquid. B) the pressure exerted on the Earth by the particles in the air. C) the temperature at which the vapor pressure of a liquid equals atmospheric pressure. D) the pressure exerted by a gas above the surface of its liquid. E) the pressure within the lungs during inhalation.

Q: The boiling point of water at sea level is 100 C. At higher altitudes, the boiling point of water will be A) lower, because temperatures are lower. B) lower, because the atmospheric pressure is lower. C) higher, because the altitude is greater. D) higher, because there are fewer water molecules in the air. E) the same, because water always boils at 100 C.

Q: A sample of helium gas at 27.0 C and 3.60 atm pressure is cooled in the same container to a temperature of -73.0 C. What is the new pressure? A) 3.12 atm B) 2.40 atm C) 5.40 atm D) 2.38 atm E) 4.15 atm

Q: A sample of argon gas at 300. C and 50.0 atm pressure is cooled in the same container to a temperature of 0.00 C. What is the new pressure? A) 105 atm B) 45.5 atm C) 54.9 atm D) 23.8 atm E) 42.7 atm

Q: A gas contained in a steel tank has a pressure of 1.5 atm at a temperature of 320 K. What will be the gas pressure when the temperature changes to 450 K, at constant moles and volume? A) 1.5 atm B) 0.94 atm C) 0.47 atm D) 2.1 atm E) 1.1 atm

Q: In Gay-Lussac's Law, the pressure of a gas increases due to an increase in temperature because A) the molecules strike the walls of the container less often. B) the molecules strike the walls of the container more often. C) the molecules get bigger. D) there is a decrease in the volume of the container. E) there is an increase in the number of gas particles.

Q: A gas at 5.00 atm pressure was stored in a tank during the winter at 5.0 C. During the summer, the temperature in the storage area reached 40.0 C. What was the pressure in the gas tank then? A) 0.625 atm B) 4.44 atm C) 5.63 atm D) 40.0 atm E) 69.5 atm

Q: A gas sample in a closed, expandable container of initial volume 5.00 L was allowed to warm from 25 C to 35 C, at constant moles and pressure. What was its new volume? A) 4.84 L B) 5.17 L C) 7.00 L D) 3.57 L E) 4380 L

Q: As the temperature of a gas increases, the density of the gas will A) increase. B) decrease. C) remain constant.

Q: The temperature of a 350. mL sample of gas increases from 27 C . to 227 C . What is the final volume of the sample of gas, if the pressure and moles in the container is kept constant? A) 583 mL B) 210. mL C) 2940 mL D) 41.6 mL E) 110. mL

Q: The volume of a sample of gas, initially at 25 C and 158 mL, increases to 450. mL. What is the final temperature of the sample of gas, if the pressure in the container is kept constant? A) 8.8 C B) 71 C C) 105 C D) -168 C E) 576 C

Q: The temperature of a 500. mL sample of gas increases from 150. K to 350. K. What is the final volume of the sample of gas, if the pressure and moles in the container is kept constant? A) 210. mL B) 1170 mL C) 0.0095 mL D) 0.0470 mL E) 110. mL

Q: What unit of temperature is used in gas law calculations? A) degrees Fahrenheit B) degrees Celsius C) Kelvin D) either degrees Celsius or degrees Fahrenheit E) either degrees Celsius or Kelvin

Q: Complete the following statement: In Charles's Law, the volume of a gas ________ when the ________ decreases. A) increases; temperature B) increases; quantity of gas C) increases; pressure D) decreases; temperature E) decreases; pressure

Q: A balloon is filled with helium gas. For the question(s) that follow, select the letter of the balloon diagram that corresponds to the given change in conditions. The temperature is changed from 50 C to -150 C at constant pressure. A) A B) B C) C D) A and B E) B and C

Q: A balloon is filled with helium gas. For the question(s) that follow, select the letter of the balloon diagram that corresponds to the given change in conditions. The balloon is put into a chamber whose pressure is less than the atmospheric pressure and at atmospheric temperature. A) A B) B C) C D) A and B E) B and C

Q: The pressure of 5.0 L of gas increases from 1.50 atm to 1240 mmHg. What is the final volume of the gas, assuming no change in moles or temperature? A) 4100 L B) 5.0 L C) 0.0060 L D) 5.4 L E) 4.6 L

Q: The volume of a gas with an initial pressure of 380 mmHg atm increases from 5.0 L to 8.0 L. What is the final pressure of the gas,in atm, assuming no change in moles or temperature? A) 238 atm B) 2.4 atm C) 0.31 atm D) 0.80 atm E) 8.0 atm

Q: The volume of a gas with a pressure of 1.2 atm increases from 1.0 L to 4.0 L. What is the final pressure of the gas, assuming no change in moles or temperature? A) 1.2 atm B) 0.30 atm C) 3.3 atm D) 4.8 atm E) 1.0 atm

Q: Which of the following correctly describes the process of inspiration (air entering the lungs)? A) The lungs expand, causing their internal pressure to decrease. B) The lungs expand, causing their internal pressure to increase. C) The lungs contract, causing their internal pressure to decrease. D) The lungs contract, causing their internal pressure to increase. E) There is no change in the internal pressure in the lungs.

Q: According to Boyle's Law, the pressure of a gas increases as the volume decreases because A) the gas particles get bigger. B) the kinetic energy of the gas particles increases. C) the temperature of the gas increases. D) the gas particles strike the walls of the container with more force. E) the gas particles strike the walls of the container more often.

Q: At constant temperature, a sample of helium at 760. torr in a closed container was compressed from 5.00 L to 3.00 L, with no change in moles or temperature. What was the new pressure exerted by the helium on its container? A) 800. torr B) 2280 torr C) 15.0 torr D) 3800 torr E) 1270 torr

Q: The air pressure on a rainy day is usually ________ air pressure on a sunny day. A) higher than B) lower than C) the same as

Q: As you rise higher in Earth's atmosphere, the atmospheric pressure A) increases. B) decreases. C) remains the same.

Q: The atmospheric pressure in Denver, CO is 633 mmHg. What is this pressure in atm? A) 1.20 atm B) 633 atm C) 0.833 atm D) 1.00 atm E) 127 atm

Q: A 5.00-L tank contains helium gas at 1.50 atm. What is the pressure of the gas in torr? A) 1.50 torr B) 507 torr C) 760 torr D) 1140 torr E) 7.5 torr

Q: A 5.00-L tank contains helium gas at 1.50 atm. What is the pressure of the gas in mmHg? A) 1.50 mmHg B) 507 mmHg C) 760 mmHg D) 1140 mmHg E) 7.5 mmHg

Q: The unit of 1 atmosphere used to describe the pressure of a gas is equal to A) 1 mmHg . B) 100 mmHg. C) 200 mmHg. D) 600 mmHg. E) 760 mmHg.

Q: Which measurement describes the pressure of a gas? A) 315 K B) 1.2 g/L C) 2.5 L D) 725 mmHg E) 0.45 moles

Q: The force of gas particles against the walls of a container is called A) pressure. B) volume. C) temperature. D) quantity of gas. E) density.

Q: In the kinetic molecular theory of gas behavior, particles of a gas tend to move ________ and collisions between them are ________. A) rapidly; rare B) slowly; rare C) rapidly; elastic D) slowly; elastic E) slowly; unusual

Q: According to the kinetic theory of gases, particles of a gas A) are very large. B) are very far apart. C) lose their valence electrons. D) move slowly. E) decrease kinetic energy as temperature increases.

Q: According to the kinetic theory of gases, a gas can be compressed much more than a liquid or solid because A) a gas is composed of very small particles. B) the particles of a gas are very far apart. C) gas particles move rapidly. D) gas particles do not attract or repel one another. E) gas particles move faster when the temperature increases.

Q: In the kinetic molecular theory of gas behavior, the assumption is made that gas molecules A) move rapidly in random directions. B) are attracted to each other by strong forces. C) are close together in their container. D) move with a kinetic energy equal to their centigrade temperature. E) occasionally come to rest.

Q: Which of the following is NOT part of the kinetic theory of gases? A) A gas is composed of very small particles. B) There is very little empty space in a gas. C) Gas particles move rapidly. D) Gas particles do not attract or repel one another. E) Gas particles move faster when the temperature increases.

Q: 4.00 moles of sodium have a mass of A) 4.60 g. B) 11.0 g. C) 23.0 g. D) 44.0 g. E) 92.0 g.

Q: What is the molar mass of Mg3(PO4)2, a substance formerly used in medicine as an antacid? A) 71.3 g B) 118 g C) 150. g D) 214 g E) 263 g

Q: The molar mass of calcium hydroxide, Ca(OH)2, is A) 58.1 g. B) 57.1 g. C) 74.1 g. D) 114.2 g. E) 38.0 g.

Q: The molar mass of C3H8O2 is A) 76.0 g. B) 60.0 g. C) 29.0 g. D) 69.0 g. E) 52.0 g.

Q: One mole of neon atoms has a mass of A) 6.02 x 1023 grams. B) 14.0 g. C) 10.0 g. D) 20.2 g. E) 30.2 g.

Q: What is the molar mass of sucrose (C12H22O11)? A) 29.0 g B) 50.2 g C) 210 g D) 342 g E) 182 g

Q: How many moles of carbon atoms are there in 0.500 mole of C2H6? A) 0.500 moles B) 1.00 moles C) 3.00 moles D) 6.02 x 1023 moles E) 4.00 moles

Q: What is the molar mass of sodium phosphate, Na3PO4? A) 119 g B) 308 g C) 164 g D) 226 g E) 354 g

Q: Calculate the molar mass of magnesium chloride, MgCl2. A) 24.3 g B) 95.2 g C) 125.9 g D) 59.8 g E) 70.0 g

Q: What is the molar mass of copper(II) sulfate, CuSO4? A) 16.0 g B) 63.6 g C) 111.6 g D) 159.6 g E) 319.2 g

Q: Calculate the molar mass of potassium chloride, KCl. A) 74.6 g B) 54.5 g C) 6.74 g D) 67.4 g E) 19.0 g

Q: 0.100 mole of lithium has a mass of A) 3.00 g. B) 0.300 g. C) 6.94 g. D) 0.694 g. E) 0.700 g.

Q: How many moles of water, H2O, are present in 75.0 g of H2O? A) 4.41 moles B) 4.16 moles C) 75.0 moles D) 7.50 moles E) 1.35 x 103 moles

Q: One mole of helium gas has a mass of A) 1.00 g. B) 2.00 g. C) 3.00 g. D) 4.00 g. E) 8.00 g.

Q: The molar mass of potassium is A) 19 g. B) 31.0 g. C) 6.02 x 1023grams. D) 39.1 g. E) 15g.

Q: How many hydrogen atoms are present in 75.0 g of H2O? A) 75.0 atoms B) 4.17 atoms C) 7.53 x 1024atoms D) 2.51 x 1024atoms E) 5.02 x 1024atoms

Q: How many molecules of water, H2O, are present in 75.0 g of H2O? A) 75.0 molecules B) 4.17 molecules C) 7.53 x 1024 molecules D) 2.51 x 1024molecules E) 5.02 x 1024molecules

Q: Avogadro's number is the number of A) particles in 1 mole of a substance. B) amu in 1 mole of a substance. C) grams in 1 mole of a substance. D) moles in 6.02 x 1023grams of an element. E) moles in 6.02 x 1023amu of an element.

Q: One mole of particles of any substance contains how many particles? A) 106 B) 3 x 10-10 C) 3 x 1010 D) 6.02 x 1023 E) 6.02 x 10-23

Q: How many atoms of neon are present in 1.30 moles of neon? A) 3.15 x 1023atoms B) 4.63 x 1023atoms C) 7.83 x 1023atoms D) 6.02 x 1023atoms E) 7.83 x 1024atoms

Q: How many moles of iron are present in 3.15 x 1024 atoms of iron? A) 5.23 moles B) 1.90 moles C) 292 moles D) 0.523 moles E) 1.90 x 1048 moles

Q: In an oxidation-reduction reaction, the substance reduced always A) takes on oxygen atoms. B) shows a loss of electrons. C) gives up hydrogen atoms. D) shows a gain of electrons. E) becomes a charged species.

Q: In this reaction, what is the substance oxidized?Zn(s) + 2 HCl(aq) -> ZnCl2(aq)+ H2(g)A) chlorineB) zinc chlorideC) hydrogenD) zincE) oxygen

Q: In an oxidation-reduction reaction, the substance oxidized always A) takes on oxygen atoms. B) shows a loss of electrons. C) gives up hydrogen atoms. D) shows a gain of electrons. E) becomes a charged species.

Q: Which of the following describes an oxidation reaction? A) loss of electrons or loss of oxygen B) loss of electrons or gain of oxygen C) loss of electrons or gain of hydrogen D) gain of electrons or gain of oxygen E) gain of electrons or loss of H