SOLVED

31) The following reaction is used to generate hydrogen gas in the laboratory. If 243 mL of gas is collected at 25°C and has a total pressure of 745 mm Hg, what mass of hydrogen is produced? A possibly useful table of water vapor pressures is provided below.             Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g) T (°C)P (mm Hg)  2017.55 2523.78 3031.86 A) 0.0196 g H2 B) 0.0717 g H2 C) 0.0190 g H2 D) 0.0144 g H2 E) 0.0449 g H2 32) A syringe contains 589 mL of CO at 325 K and 1.2 atm pressure. A second syringe contains 473 mL of N2 at 298 K and 2.6 atm. What is the final pressure if the contents of these two syringes are injected into a 1.00 L container at 273 K? A) 0.59 atm B) 1.1 atm C) 1.7 atm D) 1.9 atm E) 3.8 atm 33) What pressure would a gas mixture in a 10.0 L tank exert if it were composed of 48.5 g He and 94.6 g CO2 at 398 K? A) 39.6 atm B) 7.02 atm C) 32.6 atm D) 46.6 atm E) 58.7 atm 34) Determine the volume of O2 (at STP) formed when 50.0 g of KClO3 decomposes according to the following reaction. The molar mass for KClO3 is 122.55 g/mol.             2 KClO3(s) → 2 KCl(s) + 3 O2(g) A) 9.14 L B) 8.22 L C) 12.3 L D) 13.7 L E) 14.6 L 35) A mixture of 1.0 mol He and 1.0 mol Ne are at STP in a rigid container. Which of the following statements is true? A) Both gases have the same average kinetic energy. B) Both gases contribute equally to the density of the mixture under these conditions. C) Both gases have the same molecular speed. D) The mixture has a volume of 22.4 L E) All of the above are true. 36) Which statement is true about kinetic molecular theory? A) A single particle does not move in a straight line. B) The size of the particle is large compared to the volume of the particle. C) The collisions of particles with one another is completely elastic. D) The average kinetic energy of a particle is not proportional to the temperature. 37) Which of the gases in the graph below has the largest molar mass? A) A B) B C) C D) D E) There is not enough information to determine. 38) Calculate the root mean square velocity of nitrogen molecules at 25°C. A) 729 m/s B) 515 m/s C) 149 m/s D) 297 m/s 39) The rate of effusion of two different gases is known as A) Avogadro’s Law. B) Graham’s Law. C) Charles’s Law. D) Boyle’s Law. E) Dalton’s Law. 40) Give the definition for diffusion. A) Gas molecules mix equally. B) Gas molecules spread out in a concentration gradient. C) Gas molecules escape from a container into a vacuum through a small hole. D) average distance between collisions E) Gas molecules mix unequally.