1. b 9.a16.b)N22. e 10. bmolar mass = 28 g/mol3. c 11.ac)63.65% A4. e 12.c5. c 13. d6.e14.d17.a) and b)on next slide7. d 15. a17. c)0.131molH2O8. bvapor16. a)d)1.3 g H2Ocondensed
Fall 2013 Exam Cont’d
17. a)The can does not explode or crumple because the pressure inside the can and the pressure outside the can (from atmosphere pressure) continue to remain “balanced” or equalized. Even though more gaseous molecules are added to the can from boiling the water, they have enough kinetic energy to escape out the opening and remain equalized with the outside pressure.17. b)The can crumples because as the can cools, the gaseous water molecules do not have as much kinetic energy and some condense to a liquid. Therefore, less gas molecules are present in the can and liquid water molecules do not take up as much space (volume). So essentially there are less moles of gas in the can colliding with the walls of the container and thus not as much pressure is exerted. Now the pressure inside the container is less than the pressure outside (from atmospheric pressure) and the outside pressure exerts more force and crushes the can.