Gas Laws The Gas Laws are mathematical n
- Slides: 24
Gas Laws
The Gas Laws are mathematical n The gas laws will describe HOW gases behave. n Gas behavior can be predicted by theory. n The amount of change can be calculated with mathematical equations. n You need to know both of these: theory, and the math
Variables for Gas Laws P=pressure n V=volume n T=temperature n n=number of moles n R=gas constant n
Units for Gas Laws atm, torr, k. Pa) n V=volume (Liters or L) n T=temperature (Kelvin or K) n n=number of moles (mol) n P=pressure (mm. Hg, n R=gas constant (atm x L/mol x K)
Robert Boyle (1627 -1691)
#1. Boyle’s Law - 1662 Gas pressure is inversely proportional to the volume, when temperature is held constant. Pressure x Volume = a constant Equation: P 1 V 1 = P 2 V 2 (T = constant)
Graph of Boyle’s Law says the pressure is inverse to the volume. Note that when the volume goes up, the pressure goes down
Jacques Charles (1746 -1823)
#2. Charles’s Law - 1787 The volume of a fixed mass of gas is directly proportional to the Kelvin temperature, when pressure is held constant. This extrapolates to zero volume at a temperature of zero Kelvin.
Graph of Charles’ Law says the volume is proportional to the temperature. Note that when the volume goes up, the temp goes up
Converting Celsius to Kelvin • Gas law problems involving temperature will always require that the temperature be in Kelvin. (Remember that no degree sign is shown with the kelvin scale. ) Kelvin = C + 273 and °C = Kelvin - 273
Converting pressure • 1 atm = 760 mm. Hg • 1 atm = 760 torr • 1 atm = 101. 3 k. Pa
Converting grams to moles • 1 mole = molar mass in grams
Joseph Louis Gay-Lussac (1778 – 1850)
#3. Gay-Lussac’s Law - 1802 • The pressure and Kelvin temperature of a gas are directly proportional, provided that the volume remains constant. • How does a pressure cooker affect the time needed to cook food?
Graph of Gay-Lussac’s Law says the pressure is proportional to the temperature. Note that when the pressure goes up, the temp goes up
#4. The Combined Gas Law The combined gas law expresses the relationship between pressure, volume and temperature of a fixed amount of gas.
The combined gas law contains all the other gas laws! n If the temperature remains constant. . . n P 1 x V 1 T 1 = P 2 x V 2 T 2 Boyle’s Law
The combined gas law contains all the other gas laws! n If the pressure remains constant. . . n P 1 x V 1 T 1 = P 2 x V 2 T 2 Charles’s Law
u. The combined gas law contains all the other gas laws! u. If the volume remains constant. . . P 1 x V 1 T 1 = P 2 x V 2 T 2 Gay-Lussac’s Law
5. The Ideal Gas Law #1 Equation: PV = n. RT n Pressure times Volume equals the number of moles (n) times the Ideal Gas Constant (R) times the Temperature in Kelvin. n n. R = 0. 0802 (L x atm) / (mol x K)
The Ideal Gas Law n We now have a new way to count moles (the amount of matter), by measuring T, P, and V. P x V n= Rx. T
Ideal Gases We are going to assume the gases behave “ideally”- in other words, they obey the Gas Laws under all conditions of temperature and pressure n An ideal gas does not really exist, but it makes the math easier and is a close approximation. n Particles have no volume? Wrong! n No attractive forces? Wrong! n
Ideal Gases n There are no gases for which this is true (acting “ideal”); however, n Real gases behave this way at a) high temperature, and b) low pressure. n. Because at these conditions, a gas will stay a gas!
- Insidan region jh
- Mathematical vs non mathematical economics
- Laws of mathematical logic
- Useless laws weaken the necessary laws
- Từ ngữ thể hiện lòng nhân hậu
- Tư thế ngồi viết
- Gấu đi như thế nào
- Thẻ vin
- Thế nào là giọng cùng tên? *
- Thể thơ truyền thống
- Hươu thường đẻ mỗi lứa mấy con
- Thế nào là hệ số cao nhất
- Diễn thế sinh thái là
- Vẽ hình chiếu vuông góc của vật thể sau
- Slidetodoc
- Phép trừ bù
- Lời thề hippocrates
- Glasgow thang điểm
- đại từ thay thế
- Vẽ hình chiếu đứng bằng cạnh của vật thể
- Quá trình desamine hóa có thể tạo ra
- Thế nào là mạng điện lắp đặt kiểu nổi
- Khi nào hổ mẹ dạy hổ con săn mồi
- Các châu lục và đại dương trên thế giới
- Các loại đột biến cấu trúc nhiễm sắc thể