LEARNING HUB connecting Science curricula to everyday applications with LESSON PLANS, lab aids and more
Your One STOP Science source
In collaboration with Washington International School Team Science
​
***GREEN WRITING = info about the website construction
Chemistry 12: Gas Laws Avogadro's Law
Lorenzo Romano Amedeo Carlo Avogadro 1776-1876
Count of Quaregna and Cerreto
As a tribute to him the Avogadro Constant was named after his gas law work: 6.022 x 10^23
The AVOGADRO CONSTANT
The Avogadro number is the number of particles (atoms, molecules or ions) in ONE MOLE of the substance
Ideal gases
Prior Knowledge/Preview
Units of volume
1 mL = 1 cm^3
1000 mL = 1 L = 1 dm^3
​
MOLAR VOLUME at STP
volume of a gas at STP (Standard Temperature and Pressure), which is equal to 22.4 L for 1 mole of any ideal gas at a temperature equal to 273.15 K and a pressure equal to 1.00 atm
​
Aerospace CONNECTIONS:
Gas Laws in aerospace
Applications and examples:
Fuels--moles reacting
Breathing in Space--volume/moles in a space capsule
Temperature changes in Space
Pressure and Altitude
The AVOGADRO LAW states that the volume of a gas varies directly with the number of moles of a gas (at the same temperature and pressure)
EQUAL volumes of different gases
SAME number of moles
SAME number of particles
Under same conditions of temperature and pressure
If all contained 1 mole, the mass of each gas would be the MOLAR MASS in g
AVOGADRO"S LAW
Volume is directly proportional to the number of moles of a gas
​
Volume = V Number of moles = n
V n
V = constant x n
​
Avogadro's Law ACTIVITY
with five balloons containing different noble gases
-
QUESTION: If you have 45.0 g argon, and all the balloons are the same size, under the same conditions of temperature and pressure, what masses are in each of the other balloons?
QUESTION: If you ignore the mass of the actual latex balloon (the uninflated balloon), and just consider the mass of gas itself, which of the balloons would float in air? Reminder: take air’s composition to be 80% nitrogen and 20% oxygen with a molar mass of 28.96 g/mol.
Avogadro's Law
Gay-Lussac's Law
Ideal gases