Unit+10+-+Gas+Laws

Gas Laws

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1) Hydrogen gas exerts a pressure of 466 torr in a container. What is this pressure in atmospheres? A. 0.217 atm B. 0.466 atm __//**C. 0.613 atm**//__ (466torrs) x (1atm/760torrs) = .613atm D. 1.63 atm E. 4.60 atm 2) "The pressure of an ideal gas is inversely proportional to its volume at constant temperature and number of moles" is a statement of __Law. A. Charles's //**B. Boyle's**//__ __C. Amontons's D. Avogadro's E. Gay-Lussac's 3) "The pressure of an ideal gas is directly proportional to its absolute temperature at constant volume and number of moles" is a statement of__ __Law. A. Charles's__ __B. Boyle's //**C****. Amontons's**//__ Did not learn this, do not need to know it. __D. Avogadro's E. Gay-Lussac's 4) "The volume of an ideal gas is directly proportional to its absolute temperature at constant pressure and number of moles" is a statement of__ __Law. B. Boyle's C. Amontons's D. Avogadro's E. Dalton's 5) "The total pressure in a mixture of unreacting gases is equal to the sum of the partial pressures of the individual gases" is a statement of__ Law. A. Charles's B. Graham's C. Boyle's D. Avogadro's 6) A sample of an ideal gas has its volume doubled while its temperature remains constant. If the original pressure was 100 torr, what is the new pressure? A. 10 torr C. 100 torr D. 200 torr E. 1000 torr 7) A sample of the inert gas krypton has its pressure tripled while its temperature remained constant. If the original volume is 12 L, what is the final volume? __//**A. 4.0 L**//__ (10atm)(12L) = (30atm)(xL) 120 = 30x x = 4L B. 6.0 L C. 9 L D. 36 L E. 48 L 8) A sample of nitrogen gas at 298 K and 745 torr has a volume of 37.42 L. What volume will it occupy if the pressure is increased to 894 torr at constant temperature? A. 22.3 L __//**B. 31.2 L**//__ (745torrs)(37.42L) = (894torrs)(xL) 27877.9 = 894x x = 31.2L C. 44.9 L D. 112 L E. 380 L 9) A sample of carbon dioxide gas at 125°C and 248 torr occupies a volume of 275 L. What will the gas pressure be if the volume is increased to 321 L at 125°C? __//**A. 212 torr**//__ (248torr)(275L) = (321L)(xtorr) 68200 = 321x x = 212torr B. 289 torr C. 356 torr D. 441 torr E. 359 torr 10) A 0.850-mole sample of nitrous oxide, a gas used as an anesthetic by dentists, has a volume of 20.46 L at 123°C and 1.35 atm. What would be its volume at 468°C and 1.35 atm? A. 5.38 L B. 10.9 L C. 19.0 L E. 77.9 L 11) A sample of ammonia gas at 65.5°C and 524 torr has a volume of 15.31 L. What is its volume when the temperature is -15.8°C and its pressure is 524 torr? A. 3.69 L C. 20.2 L D. 63.5 L E. not possible, since the volume would have to be negative 12) What are the conditions of STP? A. 0 K and l atm C. 0°C and 760 atm D. 273.15°C and 760 torr E. none of these choices is correct 13) A gas mixture consists of equal masses of methane (atomic weight 16.0) and argon (atomic weight 40.0). If the partial pressure of argon is 200. torr, what is the pressure of methane, in torr? A. 80.0 torr B. 200. torr //(40g)/(40g) = 1 mol Argon. (40g)/(16g) = 2.5 mol meth. 1 + 2.5 = 3.5 mol total// C. 256 torr //1mol/3.5mol = 28.6% = 200 torr 2.5mol/3.5mol = 71.4% = xtorr// E. 556 torr 14) A gas mixture, with a total pressure of 300. torr, consists of equal masses of Ne (atomic weight 20.) and Ar (atomic weight 40.). What is the partial pressure of Ar, in torr? A. 75 torr (40g)/(40g) = 1 mol argon (40g)/(20g) = 2 mol Ne 2 + 1 = 3 mol __//**B. 100. torr**//__ 1 mol argon / 3 mol total = 1/3 total 300*(1/3) = 100torr C. 150. torr D. 200. torr E. none of these choices is correct 15) Magnesium metal (0.100 mol) and a volume of aqueous hydrochloric acid that contains 0.500 mol of HCl are combined and react to completion. How many liters of hydrogen gas, measured at STP, are produced? Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) A. 2.24 L of H2 B. 4.48 L of H2 C. 5.60 L of H2 **//__HUH?!?!?!?!__//** D. 11.2 L of H2 E. 22.4 L of H2 16) Which of the following gases effuses most rapidly? __//**A. nitrogen**//__ Lower the mass of the compound, the faster it effuses. B. oxygen C. hydrogen chloride D. ammonia E. carbon monoxide 17) Which of the following gases will be the slowest to diffuse through a room? A. methane, CH4 B. hydrogen sulfide, H2S D. water, H2O E. neon, Ne 18) A compound composed of carbon, hydrogen, and chlorine effuses through a pinhole 0.411 times as fast as neon. Select the correct molecular formula for the compound. A. CHCl3 B. CH2Cl2 C. C2H2Cl2 D. C2H3Cl E. CCl4 19) Select the gas with the highest average kinetic energy per mole at 298 K. A. O2 B. CO2 C. H2O D. H2 E. All have the same average kinetic energy. 20) Select the gas with the largest root-mean-square molecular speed at 25°C. A. NH3 B. CO C. H2 D. SF6 E. All the gases have the same root-mean-square molecular speed at 25°C.
 * //A. Charles's//**
 * //__E. Dalton's__//**
 * //__B. 50 torr__//** (100torr)(10ml) = (xtorr)(20ml) 1000 = 20x x = 50torrs
 * //__D. 38.3 L__//** (1.35atm)(xL) = (.850mol.)(741.15K)(.0821r constant) 1.35atm(xL) = 51.7 x = 38.3L
 * //__B. 11.6 L__//** (15.31L)/(338.65K) = (xL)/(257.35K) xL = 11.6L
 * //__B. 273.15 K and 760 torr__//**
 * //__D. 500. torr__//** //200/x = .286 200 = .286x x = 699.3 Pressure Total 699.3torr - 200torr = 499.3 or 500 torr//
 * //__C. carbon dioxide, CO2__//** Heaviest Molar Mass of the options