1. فشار(Pressure)

2. فشار چیست؟

3. معادلات فشار P = F/A P = نیوتن (Kg x m/s/s) عرض x طول Pascals or N/m²

4. فشار خیلی پایین فشارهای بالاتر کل سیستم فشار پایینی دارد اما در دهانه گرداب فشار بسیار پایین است و به این دلیل جریان گردابی شدیدی ایجاد می شود.

5. فشار ستونی از مایع با افزایش ارتفاع آب در ستون فشار آن نیز افزایش می یابد.

6. The first device for measuring atmospheric pressure was developed by Evangelista Torricelli during the 17 th century. The device was called a “barometer” Baro = weight Meter = measure Evangelista Torricelli, circa 1644 Measuring Pressure “We live submerged at the bottom of an ocean of air.”

7. Barometer Vacuum Height of column 29.92 in. (76 cm) Air pressure Mercury

8. Barometer Vacuum Height of column 29.92 in. (76 cm) Air pressure Mercury

9. Barometer Mercury filled 760 mm = 1 atm Water filled 10400 mm = 1 atm The barometer measures air pressure Water column (34.0 ft. high or 10.4 m) Atmospheric pressure Mercury column (30.0 in. high or 76 cm )

10. تغییرات نقطه جوش با ارتفاع Water exerts a vapor pressure of 101.3 kPa at a temperature of 100 o C. This is defined as its normal boiling point: در نقطه جوش فشار بخار مایع با فشار اتمسفری برابر می شود. x kPa = 253 mm Hg (101.3 kPa) = 33.7 kPa (760 mm Hg)

11. Manometer lower pressure higher pressure P1P1 PaPa height 750 mm Hg 130 mm higher pressure 880 mm Hg P a = h = +- lower pressure 620 mm Hg

12. Manometer PbPb PaPa 750 mm Hg P a =

13. lower pressure Manometer PaPa height 750 mm Hg 130 mm lower pressure 620 mm Hg P a = h = -

14. 880 mm Hg higher pressure higher pressure Manometer PaPa height 750 mm Hg 130 mm P a = h = +

15. Manometer PbPb PaPa 750 mm Hg P a =

16. lower pressure Manometer PaPa height 750 mm Hg 130 mm lower pressure 620 mm Hg P a = h = -

17. 880 mm Hg higher pressure higher pressure Manometer PaPa height 750 mm Hg 130 mm P a = h = +

18. جادوییU-tube Evaporates Easily VOLATILE HIGH Vapor Pressure Evaporates Slowly LOW Vapor Pressure AIR PRESSURE 15psi AIR PRESSURE 15psi AIR PRESSURE 15psi 4 psi2 الکل آب

19. Barometer Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 451 (a) (b)(c)

20. تبخیر H 2 O(g) molecules (water vapor) H 2 O(l) molecules

21. تبخیر H 2 O(g) molecules (water vapor) H 2 O(l) molecules

22. تبخیر H 2 O(g) molecules (water vapor) H 2 O(l) molecules

23. روش اندازه گیری فشار بخار 1 atm = 760 mm Hg 760 mm + 120 mm = 880 mm Hg Animation by Raymond Chang All rights reserved dropper containing a liquid atm. pressure atmospheric pressure mercury vapor from the liquid 120 mm