Can anyone simplify/help me understand Avogadro's Law?

Question

I am in 9th grade and we've been told by the teachers that at equal temperature and pressure, two gases have the same volume, same number of molecules/atoms and are identical in structure..I didn't understand...
How can this work? I mean..how is it possible?

Answer 1

I'm sorry if I am not correct in my answer. However, this is how I conceptualize it...

First, I have no idea what it means to say the gases have "identical in structure". That doesn't make sense to me.

But to understand why two different gases would have the same number of molecules/atoms is not too difficult. First you have to really try to understand what temperature is. If you are using the idea of hot and cold, then get that out of your mind for this concept. Try to find a technical answer of what temperature is in a physics book. If you can grasp it, then take those concepts that define what temperature are, and try to understand each of those individually (example: what is energy? what is mass?).. Keep drilling down into the definitions until you understand the fundamental levels of physics (like energy, mass etc..). I had a rule in school that seemed to help me learn:
The fundamentals are a most important key to understanding bigger ideas.

So, don't try to always learn the big formulas.. also try to understand where the formulas come from. How di dthey figure them out? It will help you later to figure things out without remembering so many complex formulas.

Anyway...

To answer you more directly, temperature is more of a measure of the average kinetic energy of gas particles (atoms or molecules). If you saw an atom or molecule flying around.. you can't really say what is it's temperature (hot or cold), you'd be more accurate to say what is it's kinetic energy. And the faster a atom flies, the more kinetic energy it has. Sometimes, the kinetic energy is not to visualized as an atom flying in a straight line, but it could be atoms or molecules bouncing around between other atoms (vibrating). It's not hard to imagine kinetic energy like this is it? Well, in essense, when you know the temperature of something, you know the average kinteic energy these atoms or molecules of gas have. So, the term Celsius or Fahrenheit actually can be broken down further.. but that is for you to discover more later :)

Now.. think about this.. if a baseball is thrown and flying at 100 miles per hour, it might have the SAME kinetic energy as a bowling ball flying through the air at 20 miles per hour. Because the bowling ball has much more mass, it doesn't have to travel through the air as fast to equal the enrgy of the very fast baseball.

The same concept is true for gas molecules of different kinds of gases. Consider two gases helium and propane for example. A light helium atom can have the same kinetic energy as a heavy propane molecule that's flying around.. only if the helium atom is traveling much faster than the propane molecule! ... Now, if the gases have on average equal kinetic energy (per particle), then you can understand that the gases are equal temperature.

So, if two gases have the same temperature, they have the same average energy PER particle (atom or molecule). When a SINGLE atom or molecule of the same kinetic energy as another atom or molecule hits a wall (or other obstacle or particle), it will PUSH (cause pressure) with an equal force (pressure) as the average atom or molecule of the other kind of gas particle of similar energy.

If these gases of equal temperature (equal kinetic energy per particle) are measured to be exerting the same pressure on different containers, this means their kinetic energy is distributed the same per unit volume. Since you know they already have the same energy PER PARTICLE, then all this simply means is that the same number of particles are bouncing around in the same size volume.

I don't know if this helps, but the answer might be in there somewhere for you to conceptualise.

Answer 2

When you write how is this possible, perhaps you are also visualizing the individual molecules of gas – some very small like H2, some very large like SF6. From that perspective I can understand how you might expect an equal number of the bigger molecules to take up more volume.

But remember gas is mostly empty space. The space between these molecules is thousands of time greater, than the volume of the molecule. The volume of a gas is not dependant on the size of the molecules, but rather on how hard the molecules hit the walls of the vessel (temperature).

You can compress a gas a great deal and still there is more space between the molecules is much greater than the size of the molecules. It is this vacuous property of gases that lead scientist to think about the gas molecules as if they had no size at all (not true). By considering gas in this “ideal state” scientist were able to identify a universal law (PV=nRT), that predicted the previous gas laws that they had worked with (P1V1=P2V2, or P1/T1=P2/T2).

All this gas stuff may seem trivial, but gases are the basis for engines, and pumps, and many vital chemical reactions that make our world a much cooler place

Answer 3

the two balloons you crammed won't have the comparable sort of debris, by using fact by potential of reducing the type of atmospheres from 3 to a million, you have decreased the tension by potential of a ingredient of three. once you extra advantageous the quantity from 3 to 5L, you extra advantageous it by potential of a ingredient of five/3, that's decrease than the decreased ingredient of three from in the previous. it is the reason this is diverse. in case you needed them to have the comparable sort of debris, then you definately might have crammed the 2d balloon like this: 9L, 43K, and 1atm. that would desire to be the comparable volume of debris!

Answer 4

v
____
n = a

V is the volume of the gas.
n is the number of moles in the gas.
a is a constant