Is double pressure equal to double volume?

Question

If two containers (A & B) have exactly equal capacities but A is filled with air at 20 PSI and B is filled with air at 40 PSI...

... does B contain double the volume of air because there is double pressure?

Thanks!

Answer 1

As far as I know capacity is the same thing as volume because capacity refers to the space of the containers. Volume is a three dimensional measure of the space something takes up. Pressure, on the other hand, is related to the amount of particles that exist in the space and the kinetic energy the particles hold. Thus, in this case, only the amount of matter that exists in the two containers are different (assuming same temperature), and so both containers have the same exact volume.

Answer 2

Two containers with the same capacity (which translates as volume) have the same volume, no matter how much air you pump in.

But if you double the pressure, you do double the mass of the air.

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Answer 3

Just think about it. You have these two identical containers with identical quantities (mass) of gas inside. How are you going to increase the pressure of one of the containers? Answer: by pumping more gas into the container. When the pressure has been doubled, that container will then contain twice the quantity (mass) of gas.

Can I make a comment on the wording of your question? It is very confusingly written which has led to some difficulties for people answering: You have to use scientific language and then there can be no confusion. If you had worded your question as follows, it would have been easy to understand:

Two containers (A&B)  have identical volumes. A is filled with air at a pressure of 20PSI and B is filled with air at a pressure of 40PSI. Does B contain double the mass of air as A does?

You cannot say "Does B contain double the volume of air", when you have stated that the two containers have the same volume.  

Answer 4

A column of air, water, etc, will create a pressure at the bottom, represented by PSI (Pounds per Square Inch).

Now, if you are able to concentrate and compress two equal containers of equal pressure, into a single container, what you are doing is squeezing two columns of air occupying two square inches into a single column of air of one square inch, then you will have double PSI.

It means that double volume of air will give you double PSI.

An easy way to visualize it is thinking about two large boxes of foam.  If you try and be able to squeeze both boxes into a single box, this new one will weight twice the weight of each original boxes, and of course the weight (and pressure) per square inch at the bottom will also double.

And yes, this double pressure box of foam will have the same volume of the previous two.  You also may say it has double density.

Answer 5

Using boyle's law, at constant temperature, double pressure would actually mean half the volume... according to boyle's law, at constant temp, the volume and pressure are inversely proportional to each other.. therefor doubling one would mean halving the other.. also think of this.. when you add pressure to something, you tend to shrink it.. its like sueezing a piece of paper, you're trying to remove all the air to make it flat thereby decreasing the volume in the process

HOPE THIS HELPS