August 11, 2020, 12:07:10 AM
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#### Speedystar777

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« on: June 05, 2020, 11:03:43 PM »
I was trying to prove the combined gas law to myself, but ended up with an equation that contradicts Boyle’s Law. What logical fallacies did I make?
« Last Edit: June 06, 2020, 04:13:46 AM by Borek »

#### Meter

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##### Re: Contradiction in pressure laws
« Reply #1 on: June 06, 2020, 08:33:45 AM »
Your algebra is obviously correct. Your problem is in your interpretation of the laws. Remember what each law assumes as an initial condition and how that differs between the laws.

#### Babcock_Hall

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##### Re: Contradiction in pressure laws
« Reply #2 on: June 06, 2020, 09:29:27 AM »
I think learning by doing one's own derivations is a fine way to proceed, and making mistakes is an important part of the learning process.

#### MNIO

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##### Re: Contradiction in pressure laws
« Reply #3 on: June 07, 2020, 02:01:27 PM »
try it like this... we're starting with V1 at constant T and n... and converting it to V'
.. P1V1 = P2V'

then if you start with V' at T1 and P1 and convert it to V2 at constant P and n
.. V' / T1 = V2 / T2

subbing
.. P1V1 = P2 * (T1 * V2 / T2)

you get to rearrange
« Last Edit: June 07, 2020, 05:38:25 PM by MNIO »