5 4 5 5 Applying The Ideal Gas

The Ideal Gas Law • If we combine three simple gas laws, we end

Let’s Try a Sample Problem An 8. 50 L tire contains 0. 552 mol

Let’s Try Another What volume does 0. 556 mol of gas occupy at a

Molar Volume and Molar Density If we were to rearrange the ideal gas law

Let’s Try a Sample Problem Calculate the density of xenon gas at a pressure

Let’s Try Another A sample of gas has a mass of 827 mg. Its

Chapter 5 pgs. 239 -240 #’s 38, 40, 44, 56, & 58 Read 5.

Slides: 8

Download presentation

5. 4 – 5. 5: Applying The Ideal Gas Law PV ----n. T

The Ideal Gas Law • If we combine three simple gas laws, we end up with a proportionality constant known as the ideal gas constant(R): PV R = -----n. T By plugging in values for pressure, volume, temperature and moles at STP, we receive the ideal gas constant (located on your reference table). MAKE SURE YOU CHECK UNITS WHEN USING THIS CONSTANT!!! The ideal gas law: PV = n. RT also locate on your reference table

Let’s Try a Sample Problem An 8. 50 L tire contains 0. 552 mol of gas at a temperature of 305 K. What is the pressure (in atm) of the gas in the tire? n. RT (0. 552 mol) (0. 08206 L atm / mol K) (305 K) P = --------------------------V 8. 50 L P = 1. 63 atm

Let’s Try Another What volume does 0. 556 mol of gas occupy at a pressure of 715 mm. Hg and a temperature of 58 o. C? n. RT (0. 556 mol)(62. 36 L mm. Hg / mol K)(331 K) V = ---------------------------P 715 mm. Hg V = 16. 1 L

Molar Volume and Molar Density If we were to rearrange the ideal gas law to solve for volume at STP (ST = 0 o. C or 273 K) and (SP = 1. 00 atm or 760 mm. Hg) we end up with the volume of a mole of any gas! Molar volume = 22. 4 L What is the formula for density? What are the units when referring to a liquid or gas? m (in grams) D= ---------V (in liters) With this formula, you can see that the quotient of molar mass of a gas and molar volume of that same gas, is the gases molar density(d). Molar density is directly proportional to molar mass (M). PM Therefore: d = ----RT

Let’s Try a Sample Problem Calculate the density of xenon gas at a pressure of 742 mm. Hg and a temperature of 45 o. C. PM (742 mm. Hg)(131. 29 g/mol) d = -----------------------RT (62. 36 L mm. Hg / mol K)(318 K) d = 4. 91 g/L

Let’s Try Another A sample of gas has a mass of 827 mg. Its volume is 0. 270 L at a temperature of 88 o. C and a pressure of 975 mm. Hg. Find the molar mass. d. RT ((0. 827 g/0. 270 L)(62. 36 L mm. Hg / mol K)(361 K) M = ---------------------------P 975 mm. Hg M = 70. 7 g/mol

Chapter 5 pgs. 239 -240 #’s 38, 40, 44, 56, & 58 Read 5. 6 -5. 7 pgs. 213 -222