Avogadro's Law e5u2b

WORD SPLASH indirectl y Characteristic s Gas

gaseous

1.States of Matter are identified as Solid, Liquid and _________ 2.Avogadro’s Law states that at _________ temperature and________, the ______is directly proportional to the number of _______ of gas. 3.The Kinetic Molecular Theory is a single set of descriptive __________of a substance known as the ___________.

1.States of Matter are identified as Solid, Liquid and Gas. 2.Avogadro’s Law states that at constant temperature and pressure, the volume is directly proportional to the number of moles of gas. 3.The Kinetic Molecular Theory is a single set of descriptive characteristics of a substance known as the Ideal Gas.

AVOGADRO’S LAW

AVOGADRO’S LAW Volume (L) 2.50 5.00 7.50 10.00 12.50

No. of Moles (mol) 0.50 1.0 1.5 2.0 2.5

V/n (L/mol)

AVOGADRO’S LAW Pressure (P)

Temperature (T)

Volume (V)

Amount of substance (n)

Directly Proportional

CONSTANT

AVOGADRO’S LAW The volumes of gases can be compared at STP, Standard Temperature and Pressure, when they have the same temperature. Standard temperature (T) 0°C or 273 K the same pressure. Standard pressure (P) 1 atm (760 mm Hg)

At standard temperature and pressure (STP), 1 mole of a gas occupies a volume of 22.4 L, which is called its molar volume.

AVOGADRO’S LAW If 0.75 mole helium gas occupies a volume of 1.5 L, what volume will 1.2 moles helium occupy at the same temperature and pressure? a) 0.94 L b) 1.8 L c) 2.4 L

AVOGADRO’S LAW c) 2.4 L STEP 1 Conditions 1 V1 = 1.5 L n1 = 0.75 mole He

Conditions 2 V2 = ??? n2 = 1.2 moles He

STEP 2 Solve for unknown V2 V2 = V1 x n2 n1 STEP 3 Substitute values and solve for V2. V2 = 1.5 L x 1.2 moles He = 2.4 L 0.75 mole He

AVOGADRO’S LAW • If 2.4 moles of gas occupies a volume of 60 L at a certain temperature, what volume will 3.7 moles of gas occupy?

AVOGADRO’S LAW • Given:

N1 = 2.4 mol V1 = 60 L

n2 = 3.7 mol V2 = ?

• Required: V2 𝑉1𝑛2 • Equation: V2 = 𝑛1 • Solution: V2 = 60 𝐿 (3.7 𝑚𝑜𝑙) (2.4 𝑚𝑜𝑙)

• Answer: 92.5 L

AVOGADRO’S LAW • A sample of gas with a volume of 9.20 L is known to contain 1.225 mol. If the amount of gas is increased to 2.85 mol, what new volume will result if the temperature and pressure remain constant?

AVOGADRO’S LAW • G:

N1 = 1.25 mol V1 = 9.20 L

• R: V2 𝑉1𝑛2 • E: V2 = 𝑛1 • S: V2 = 9.20 𝐿 (2.85 𝑚𝑜𝑙) (1.25 𝑚𝑜𝑙)

• A: 21.4 L

n2 = 2.85 mol V2 = ?

AVOGADRO’S LAW • If 0.25 mol of argon gas occupies a volume of 7.62 mL at a particular temperature and pressure, what volume would 0.43 mol of argon have under the same conditions?

AVOGADRO’S LAW • G:

N1 = 0.25 mol V1 = 7.62 mL

• R: V2 𝑉1𝑛2 • E: V2 = 𝑛1 • S: V2 = 7.62 𝑚𝐿 (0.43 𝑚𝑜𝑙) (0.25 𝑚𝑜𝑙)

• A: 13.1 mL

n2 = 0.43 mol V2 = ?

AVOGADRO’S LAW • At certain temperature and pressure, a balloon with 10.0g of oxygen has a volume of 7.00 L. what is the volume after 5.00 g of oxygen is added to the balloon?

AVOGADRO’S LAW • G:

N1 = 10.0g V1 = 7.00 L

• R: V2 𝑉1𝑛2 • E: V2 = 𝑛1 • S: V2 = 7.00𝐿 (15.00 𝑚𝑜𝑙) (10.00 𝑚𝑜𝑙)

• A: 10.5 L

n2 = 15.00 mol V2 = ?

AVOGADRO’S LAW • What would be the volume of 3.0 moles of hydrogen gas at Standard Temperature and Pressure? (at STP, 1.0 mole of any gas is contained in 22.4 L)

AVOGADRO’S LAW

Vol 3.0 mol H2 =

3.0 𝑚𝑜𝑙 (22.4 𝐿) (1.0 𝑚𝑜𝑙)

= 67.2 L

IDEAL GAS LAW BOYLES LAW

CHARLES’ LAW

AVOGADRO’S LAW

IDEAL GAS LAW

IDEAL GAS LAW 1 𝑃

• Boyle’s Law: V α (n and T are constant) • Charles Law: V α T (n and P are constant)

• Avogadro’s Law: V α n ( and T are constant) Combining the three laws we can get: Vα=

𝑛𝑇 𝑃

IDEAL GAS LAW Using the sign of equality will result to this equation: V=

𝑛𝑅𝑇 𝑃

or PV = NRT Ideal Gas Law

Where: V = volume in liters P = pressure in atmosphere n = moles T = temperature in Kelvin R = universal gas constant 0.0821 L atm mol. K.

AVOGADRO’S LAW  What is the volume of the container that can hold 0.50 mole of gas at 25.0 °C and 1.25 atm?

AVOGADRO’S LAW • G:

Pressure: 1.25 atm Temperature: 25°C + 273 = 298 K No. of moles: 0.50 moles

• R: V=? 𝑛𝑅𝑇 • E: V = 𝑃 • S: V= 0.50 𝑚𝑜𝑙𝑒

• A: 9.8 L

𝑎𝑡𝑚 (0.0821 𝐿 .𝐾)(298 𝐾) 𝑚𝑜𝑙

1.25 𝑎𝑡𝑚

AVOGADRO’S LAW  Calculate the pressure exerted by a 0.25 mole sulfur hexafluoride in a steel vessel having a capacity of 1,250 mL at 70°C

AVOGADRO’S LAW • G:

Pressure: 0.25 atm Temperature: 70°C + 273.15 = 298.15 K Volume: 1,250 mL

• R: P=? • E: P = • S: V =

𝑛𝑅𝑇 𝑉

0.25 𝑚𝑜𝑙𝑒 (0.0821 𝐿.𝑎𝑡𝑚/𝑚𝑜𝑙)(70.0+273.15𝐾) (1.25𝐿)

• A: 0.56 atm / 5.6 atm

AVOGADRO’S LAW  Fermentation of glucose produce gas in the form of carbon dioxide. How many moles of carbon dioxide is produced if 0.78 L of carbon dioxide at 20.1°C and 1.00 atm was collected during the process?

AVOGADRO’S LAW • G:

Volume: 0.78L Temperature: 20.1°C + 273.15 = 293.25 K Pressure: 1.00 atm

• R: n=? • E: n = • S: n =

𝑃𝑉 𝑅𝑇

1.00 𝑎𝑡𝑚 (0.78 𝐿) (0.0821 𝐿.𝑎𝑡𝑚/𝑚𝑜𝑙)(20.1+273.15 𝐾)

• A: 0.032 mole CO2

AVOGADRO’S LAW  A sample of liquid acetone is placed in a 25.0 mL flask and vaporized by the heating to 75°C at 1.02 atm.Calculate the number of moles of the acetone.

AVOGADRO’S LAW • G:

Volume: 25.0 L Temperature: 75°C + 273.15 = 348.15 K Pressure: 1.02 atm

• R: n=? 𝑃𝑉 • E: n = 𝑅𝑇 • S: n =

1.02 𝑎𝑡𝑚 (0.0250 𝐿) (0.0821 𝐿.𝑎𝑡𝑚/𝑚𝑜𝑙)(75+273.15 𝐾)

• A: 8.92 x 10 -4 mole of acetone