Quarter4_ModuleI_different laws of gases.pptx

Science 10

1. QUARTER 4: MODULE 1 BEHAVIOR OF GASES WEK 1 & 2

2. Activity 1. Arrange Me! Directions: Arrange the jumbled letters to get its correct word. 1. TKICIEN LOLRCUEMA RYOEHT 2. TRORBE YLEOB 3. QASECUJ SCLEARH 4. LEIDA AGS 5. YGA-CSASLU - 6. BDOMIECN SAG – 7. MEPETTREURA 8. SSPREERU – 9. MELOVU – 10. RODAGOVA

3. Lesson 1.1: BOYLE’S LAW - Robert Boyle in 1662 - The molecules of a gas exert pressure on the walls of its container . - When pressure is applied on the gas , the molecules move closer to one another which result in the decrease in volume. This increases the chances of collisions among the molecules and the walls of the container; thus, pressure is increased.

4. Boyle’s law can be expressed mathematically as P 1/V at constant temperature To remove the proportionality sign, we introduce the constant k P = k 1/V Therefore, k=PV If the same gas is brought into different pressures, it will give two different volumes, with the same value for k. Then the equation will become P1V1=P2V2 Where: P1 = initial pressure P2 = final pressure V1 = initial volume V2 = final volume Any unit of pressure and volume may be used. However, uniformity of units must be observed.

5. Table 1. Commonly used units and their equivalents for volume, pressure and temperature Variable SI Unit Metric Unit English Unit Units and their equivalents Volume cubic meter (𝑚3) cubic decimeter (𝑑𝑚3) cubic centimeter (𝑐𝑚3) liter(L) milliliter(mL quart(qt) gallon(gal) 1 mL = 1 𝑐𝑚3 1 L = 1 𝑑𝑚3 1 𝑐𝑚3=1000 L Pressure Pascal (Pa) atmosphere(atm) millimeters of mercury(mm Hg) centimeters of mercury (cm Hg) torr lb /𝑖𝑛2 (psi) 1 atm = 760 mm Hg = 76 cm Hg = 760 torr = 101,325 Pa = 14.6956 psi Temperature Kelvin(K) Celsius(°C) Fahrenhei t(°F) 0 °C = 273.15 K 0 °C = 32 °F

6. Activity 2. Let’s solve! Directions: Answer the following problem. Write your answers on a separate sheet of paper. 1. The inflated balloon that slipped from the hand of Renn has a volume of 0.50 L at sea level (1.0 atm) and it reached a height of approximately 8 km where the atmospheric pressure is approximately 0.33 atm. Assuming that the temperature is constant, compute for the final volume of the balloon. 2. Oxygen gas inside a 1.5 L-gas tank has a pressure of 0.95 atm. Provided that the temperature remains constant, how much pressure is needed to reduce its volume by ½ ?

7. Lesson 1.2: CHARLE’S LAW -One of the variable that affects the volume of a gas is the temperature of the gas and its surroundings. - 1787, Jacques Charles - He concluded that when the pressure of a gas is kept constant, its volume is directly proportional to its temperature. This means that the volume of a gas increases as the temperature rises and the volume decreases as the temperature drops. This relationship is now known as Charles’ Law.

8. - Charles law can be expressed mathematically as V T at constant pressure To remove the proportionality sign, we introduce the constant k V = k T Therefore, k = 𝑉/𝑇 If the same gas is brought to two different temperatures, it will give two different volumes. The equation will become 𝑉1/𝑇1=𝑉2/𝑇2 where: T1 = initial temperature of the gas V1 = initial volume of the gas T2 = final temperature of the gas V2 = final volume of the gas Any unit of volume may be used, provided that the unit of V1 and V2 are the same. However, only Kelvin scale may be used for temperature.

9. Table 2. Temperature Conversion Formulas Celsius to Fahrenheit °F =9/5 (°C ) + 32 Kelvin to Fahrenheit °F = 9/5 (K - 273 ) + 32 Fahrenheit to Celsius °C = 5/9(°F - 32 ) Celsius to Kelvin K = °C + 273 Kelvin to Celsius °C = K - 273 Fahrenheit to Kelvin K =5/9 (°F - 32 ) + 273

10. - Activity 3. Solve Me! Directions: Answer the following problem regarding Charles Law. Write your answers on a separate sheet of paper. A gas occupies 900.0 mL at a temperature of 27.0 °C. What is the volume at 132.0 °C? 2. Calculate the decrease in temperature (in Celsius) when 2.00 L at 21.0 °C is compressed to 1.00 L?

11. - Lesson 1.3: GAY-LUSSAC’S LAW Gay-Lussac’s law can be expressed mathematically as P T at constant volume To remove the proportionality sign, we introduce the constant k P = k T Therefore, k = 𝑃/𝑇 Since there is a direct proportionality between the pressure and temperature of gases at constant volume, it can be shown in this equation 𝑃1/𝑇1=𝑃2/𝑇2

12. Activity 4. Try Me! Directions: Answer the following problem. Write your answers on a separate sheet of paper. The helium tank has a pressure of 650 torr at 25 °C. What will be the pressure if the temperature is tripled? 2. A tire is filled to a gauge pressure of 2 atm at 27°C. After a drive, the temperature within the tire rises to 47°C. What is the pressure within the tire now?

13. Lesson 1.4:Combined Gas Law The combined gas law combines the three gas laws: Boyle's Law, Charles' Law,and Gay-Lussac's Law. It states that the ratio of the product of pressure and volume and the absolute temperature of a gas is equal to a constant. Unlike the named gas laws, the combined gas law doesn't have an official discoverer. It is simply a combination of the other gas laws that works when everything except temperature,pressure , and volume are held constant.

14. There are a couple of common equations for writing the combined gas law. The classic law relates Boyle's law and Charles' law to state: PV/T = k where P = pressure, V = volume, T = absolute temperature (Kelvin), and k = constant. The constant k is a true constant if the number of moles of the gas doesn’t change. Another common formula for the combined gas law relates "before and after" conditions of a gas:𝑃1𝑉1/𝑇1= 𝑃2𝑉2/𝑇2

15. Activity 5.Do you know my solution! Directions: Read and answer the following problem. Write your answers on a separate sheet of paper. The initial temperature of a 1.00 liter sample of argon is 20°C. The pressure is decreased from 720 mm Hg to 360 mm Hg and the volume increases to 2.14 liters. What was the change in temperature of the argon in Celsius? 2. The volume of a gas at 27°C and 700 mm Hg is 600 mL. What is the volume of the gas at -20.0 °C and 500 mm Hg?

16. Lesson 1.5: Avogadro’s Law When you blow up a balloon, its volume increases because of the addition of more air molecules. If a ball is punctured and some of the air leaks out, its volume decreases. In this lesson, you will consider how the properties of a gas change when there is a change in the number of moles or grams. Amedeo Avogadro in 1811 stated that the volume of a gas is directly related to the number of moles of a gas when the temperature and pressure are not changed. If the moles of a gas are doubled, then the volume will double as long as the pressure and temperature remain the same.

17. Mathematically, the Avogadro’s Hypothesis can be expressed as 𝑉/𝑛 = k Where, V is the volume of gas, n is the amount of gas in moles and k is a proportionally constant. This can also expressed as: 𝑉1/𝑛1 = 𝑉2/𝑛2 or V1n2 = V2n1

18. Activity 6.Find my value! Directions: Read and answer the following problem. Write your answers on a separate sheet of paper. A 7.25 L sample of nitrogen gas (𝑁2) is identified to contain 0.75 mole of nitrogen. How many moles of nitrogen gas would there be in a 20.0 L sample provided the temperature and pressure remains the same? 2. 5.00 L of a gas is known to contain 0.965 mol. If the amount of gas is increased to 1.80 mol, what new volume will result (at an unchanged temperature and pressure)?

19. Lesson 1.6: IDEAL GAS LAW