Learning Log

1. Learning Log • Read “How it Works” on p. 377 of resource text and answer questions #1 and 2.

2. Demos - Its all about pressure • Crushing can • Card trick • Egg in a flask

3. V T P Ch. 10 & 11 - Gases II. The Gas Laws(p. 313-322)

4. Definition of Gas Laws V P P T T V • Simple mathematical relationships between the volume, temperature, pressure and amount of a gas.

5. A. Boyle’s Law P V PV = k

6. A. Boyle’s Law

7. A. Boyle’s Law P V • The pressure and volume of a gas are inversely related • at constant mass & temp PV = k

8. A. Boyle’s Law • P1 = initial pressure • V1 = initial volume • P2 = final pressure • V2 = final volume • P1V1 = k and P2V2 = k; therefore, P1V1 = P2V2

9. Practice Problem – Boyle’s Law • A sample of oxygen gas has a volume of 150. mL when its pressure is 0.947 atm. What will the volume of the gas be at a pressure of 0.987 atm if the temperature remains constant? • V2 = P1V1 = (0.947 atm)(150. mL O2) P2 0.987 atm =144 mL O2

10. B. Charles’ Law

11. B. Charles’ Law V T

12. B. Charles’ Law V T • The volume and absolute temperature (K) of a gas are directly related • at constant mass & pressure

13. B. Charles’ Law • T1 = initial temperature • V1 = initial volume • T2 = final temperature • V2 = final volume • V1 = k and V2 = k; therefore, T1 T2 V1 = V2 T1 T2

14. Practice Problem – Charles’ Law • A sample of neon gas occupies a volume of 752 mL at 25 °C. What volume will the gas occupy at 50°C if the pressure remains constant? • V2 = V1T2 = (752 mL Ne) (323 K) T1 298 K =815 mL Ne

15. Practice • Read p. 146-152 in workbook and complete problems #1-5 on pp. 149-150 and problems #1-3 on pp. 153-154.

16. Learning Log • Read “How it Works” on p. 387 of resource text and answer questions #1 and 2.

17. Charles’ Law Demonstration

18. C. Gay-Lussac’s Law P T

19. C. Gay-Lussac’s Law P T • The pressure and absolute temperature (K) of a gas are directly related • at constant mass & volume

20. C. Gay-Lussac’s Law • P1 = initial pressure • T1 = initial temperature • P2 = final pressure • T2 = final temperature • P1 = k and P2 = k; therefore, T1 T2 P1 = P2 T1 T2

21. Practice Problem – Gay-Lussac’s Law • The gas in an aerosol can is at a pressure of 3.00 atm at 25°C. Directions on the can warn the user not to keep the can in a place where the temperature exceeds 52°C. What would the gas pressure in the can be at 52°C? • P2 = P1T2 T1 P2 = (3.00 atm)(325 K) = 3.27 atm 298 K

22. D. Combined Gas Law P1V1 T1 P2V2 T2 = PV T = k P1V1T2 =P2V2T1

23. D. Combined Gas Law Boyle’s Law: P1V1T2 = P2V2T1 P1V1=P2V2 Charles’s Law: P1V1T2 = P2V2T1 V1T2 = V2T1 Gay-Lussac’s Law: P1V1T2 = P2V2T1 P1T2=P2T1

24. E. Gas Law Problems • A gas occupies 473 cm3 at 36°C. Find its volume at 94°C. CHARLES’ LAW GIVEN: V1 = 473 cm3 T1 = 36°C = 309K V2 = ? T2 = 94°C = 367K T V WORK: P1V1T2 = P2V2T1 (473 cm3)(367 K)=V2(309 K) V2 = 562 cm3

25. E. Gas Law Problems • A gas occupies 100. mL at 150. kPa. Find its volume at 200. kPa. BOYLE’S LAW GIVEN: V1 = 100. mL P1 = 150. kPa V2 = ? P2 = 200. kPa P V WORK: P1V1T2 = P2V2T1 (150.kPa)(100.mL)=(200.kPa)V2 V2 = 75.0 mL

26. E. Gas Law Problems • A gas’ pressure is 765 torr at 23°C. At what temperature will the pressure be 560. torr? GAY-LUSSAC’S LAW GIVEN: P1 = 765 torr T1 = 23°C = 296K P2 = 560. torr T2 = ? P T WORK: P1V1T2 = P2V2T1 (765 torr)T2 = (560. torr)(309K) T2 = 226 K = -47°C

27. E. Gas Law Problems • A gas occupies 7.84 cm3 at 71.8 kPa & 25°C. Find its volume at STP. COMBINED GAS LAW P T V GIVEN: V1=7.84 cm3 P1=71.8 kPa T1=25°C = 298 K V2=? P2=101.325 kPa T2=273 K WORK: P1V1T2 = P2V2T1 (71.8 kPa)(7.84 cm3)(273 K) =(101.325 kPa)V2 (298 K) V2 = 5.09 cm3

28. Practice • Read pp. 154-160 and complete problems #1-3 on pp. 157-158 and #1-2 on p. 161.