Tham khảo tài liệu 'sat ii physics (gary graff) episode 1 part 7', ngoại ngữ, ngữ pháp tiếng anh phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | THERMAL PROPERTIES OF MATTER Solution We can sum these relationships with an equation called the Ideal Gas Law. PV nRt P pressure expressed in -N-or Pa m V volume expressed in m3 or compatible units N number of moles and or mass of gas n molecular mass R gas law constant k T temperature in Kelvins J mole K 1 atmosphere of pressure X 105 Pa or 101KPa Standard temperature and pressure are defined as 1 atmosphere of pressure and a temperature of 273 K. Any gas that obeys the Ideal Gas Law is called an ideal gas. Example A 500cm3 5 X 10 4m3 container is filled with chlorine gas. How many moles of the gas are in the container at STP Solution PV nRt State and rearrange the equation. PV n RT X 105Pa 5 X10-4 m3 n __ J . J V 273K mole K n X10-2 moles .022 moles Peterson s 145 CHAPTER 4 Boyle s Law and Charles Law The relationship between pressure and volume was studied by Robert Boyle 1627-1691 who gave us the statement called Boyle s Law. Boyles Law states that when the temperature of a gas is kept constant the pressure will vary inversely with the volume. A few years later Jacques Charles 1746-1823 added his statements about the relationships between pressure temperature and volume which are known as Charles Law. 1. If the pressure of a gas is held constant the volume of a gas is directly proportional to its absolute temperature. 2. At constant volume the pressure of a gas is proportional to the absolute temperature. Boyle s Law can be stated as an equation. P1V1 PV Charles Law can also be stated in equation form. V T V P - 2 or the variation T T 2 1 P Tl Combining the three equations above gives another useful equation called the Combined Gas Law. P1 V PJVl T T2 Notice a difference in the Combined Gas Law compared to the Ideal Gas Law PV nRt . Pressure and volume units may be expressed in any units that are compatible to one another. Temperature though still relative to absolute or Kelvin values may be left in .
