11 Properties of Gases

Transcription

1 South asadena Honors Chemistry Name 11 roperties of Gases eriod Date S A I O N 1 E M E R A U R E Standard emperature is: 0 C or 273 K Convert: 26.0 C 299 K 400 K _127 C 100 K 173 C 135 C _408_ K -127 C _146 K 4 K _ 269 C What is the temperature of a sample of gas that has double the kinetic energy (motion energy) of a sample of gas at 80 C? 80 C 353 K. A sample of gas with double the KE has temperature 2(353 K) 706 K 433 C. In Kinetic Molecular heory, the temperature is the: average kinetic energy of a sample 11 roperties of Gases S A I O N 2 R E S S U R E U N I S Standard ressure is: 1 atm 760 mmhg 760 torr 14.7 psi ka Make the following conversions: (Show your work) 550 mmhg? ka 55 psi? mmhg 550 mmhg ka 760 mmhg 73.3 ka 55 psi 760 mmhg 2844 mmhg 14.7 psi 325 ka? atm 2284 torr? ka 325 ka 1 atm ka 3.21 atm 2284 torr ka 305 ka 760 torr 48.0 mmhg? torr 1.85 atm? mmhg 48.0 mmhg 760 torr 760 mmhg 48.0 torr 1.85 atm 760 mmhg 1406 mmhg 1 atm g of CH 4 and g of He are placed in a rigid container. he total pressure of the gas mixture is 1.45 atm. What is the partial pressure of each gas? 125 g CH 4 1 mol CH mol CH g CH g He 1 mol He mol He mol total g He CH mol CH mol total (1.45 atm) atm CH4 He mol He (1.45 atm) atm He mol total In Kinetic Molecular heory, the pressure describes: collisions of gases against the walls of the container.

2 11 roperties of Gases S A I O N 3 G A S L A W R O B L E M S Solve the problem. Show your work using I.E.S.A. 1. A balloon has a volume of 5.00 L at 2.50 atm. What is the balloon s volume at 1.50 atm? atm L atm 2? (2.50 atm)(5.00 L) (1.50 atm)( 2) L 8.33 L 2. A balloon has a volume of 3.50 L at 21.0 C when the air pressure is 1.05 atm. How many moles of gas are contained in the balloon? 1.05 atm 3.50 L n? 294 K n R (1.05 atm)(3.50 L) (n)(0.0821)(294 K) n mol mol 11 roperties of Gases S A I O N 4 M O R E G A S L A W R O B L E M S Solve the problem. Show your work using I.E.S.A. 1. A balloon at 35 C has a volume of 2.5 L. What is its volume at 45 C? L K 2? K L 308 K K L 2. A balloon has a volume of 1.0 L at 21.0 C and 750 mmhg. What is the balloon s volume at S? 2.58 L mmhg L K mmhg 2? K (750 mmhg)(1.0 L) 294 K L (760 mmhg)(2) 273 K 9.16 L

3 11 roperties of Gases S A I O N 5 K I N E I C M O L E C U L A R H E O R Y Explain the following observations in terms of the kinetic molecular theory (that is, what do the gas particles look like?) A balloon of gas is placed in a car on a hot day. he balloon gets larger. Explain. As the temperature increases, the gas particles move faster and collide with the walls of the balloon more often. he volume of the balloon increases until the particles collide with the walls at the same rate (same pressure). A syringe is squeezed so the gas sample changes from 10 cc to 5 cc. he pressure doubles. When the gas is squeezed, the distance particles must travel between collisions with the container wall is shorter so the number of collisions increases. 11 roperties of Gases A 10.0 gram chunk of dry ice (solid CO 2) changes to gas. What is the volume of that gas measured at 27 C and 740 mmhg? S A I O N 6 I D E A L G A S L A W 740 mmhg? n 10.0 g 1 mol CO mol g CO 2 n? n R 300 K (740 mmhg) 1 atm () (0.227 mol)(0.0821)(300 K) 760 mmhg 5.75 L 5.75 L What is the density of the gas? D m 10.0 g 1.74 g/l 5.75 L

4 11 roperties of Gases S A I O N 7 I D E A L G A S L A W Calculate the moles of a gas sample if 3.0 grams of the gas in a 2.0 L container at 25 C has a pressure of atm atm 2.0 L n? 298 K n R (2.294 atm)(2.0 L) (n)(0.0821)(298 K) n mol mol Calculate the molar mass of the gas. MM m n 3.0 g 16.0 g/mol mol 11 roperties of Gases S A I O N 8 G R A H A M S L A W 1 mole each of He gas and CO 2 gas are in a rigid container at the same temperature. he kinetic energy of He is the same as (greater than, less than, the same as) the kinetic energy of CO 2. he velocity of He is _greater than (greater than, less than, the same as) the velocity of CO 2. Calculate the ratio of the velocities of He/CO 2. v He MM CO v CO2 MM He When HCl(g) and NH 3(g) come in contact, they form a white solid, NH 4Cl(s). If samples of the two gases are placed at the ends of a tube, the white solid will appear closest to point b? HCl a b c d e NH 3 v NH3 v HCl MM HCl MM NH

5 11 roperties of Gases Sketch the graph of the following pairs of variables: S A I O N 9 G R A H S O F A R I A B L E S n Circle the Law that would relate each pair of variables: constant constant constant n constant constant constant constant n constant