Pressure Units
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Pressure Units
Hi! In this class, is there an official unit of pressure we will be using/should be converting to in problems? I know that atm and bar are very similar quantitatively, but I'm not sure if there is one that is preferred.
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Re: Pressure Units
As long as you are making sure you are being consistent with your units while computing, I don't think there is a preference between units. Because you will end up with a right answer if you are being consistent. From my experience in chemistry classes atm is used more than bar, but again, just know to be familiar with them both and ensure your units are the same throughout a computation.
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Re: Pressure Units
I don't believe there is a preferred unit; I would use whatever unit is given in a problem. Either way, just be sure you are consistent within a problem so you don't get units mixed up; you can always convert at the end if need be.
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Re: Pressure Units
I don't think Dr. Lavelle has said anything specific to an official unit of pressure. But as long as your units are consistent and you know how to solve problems including pressure, you should be fine. If it is the wrong unit, you could always use a conversion factor to change the units at the end.
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Re: Pressure Units
I think as long as you're consistent with units you can always convert at the end to whatever unit the equation wants by converting.
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Re: Pressure Units
From what I've gathered during lectures, Lavelle hasn't stated any official unit that we should always be computing for. He will give us the appropriate unit in the problem and expect us to be consistent with said unit while computing. That being said, we should be familiar with the bar and atmosphere units that you mentioned.
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Re: Pressure Units
I echo what everyone else said, however it is important to convert everything to bar when you are given a Kp because that value is calculated using bar.
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Re: Pressure Units
I believe you can use either atm or bars, but it depends on the problem in question.
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Re: Pressure Units
I would personally stick to whichever units are used in the problem unless it specifically states that it needs to be converted to a different unit. It just makes it easier on yourself :)
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Re: Pressure Units
I think as long as you convert are pressure values in the problem to the same unit and then solve the problem, you can use whichever unit. However, Pa is the SI unit for pressure, so I tend to stick to that.
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Re: Pressure Units
I believe you should be consistent with whichever units are used in the problem and you should be good.
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Re: Pressure Units
There is no official unit, but the SI unit for pressure is Pascal. Atm and bar are also used, it depends on the problem. Whichever unit is used, the important thing is to keep the units consistent or according to the problem.
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Re: Pressure Units
I think if you are consistent with your units while you are computing and giving a final answer it does not matter what you use. You can use either atm, bar, or pascal.
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Re: Pressure Units
We have not been told which units they prefer, but I'm assuming it will depend on the question that we are answering and making sure units are consistent.
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Re: Pressure Units
I don't think that there is a preferred unit, although pascals are the SI unit for pressure. I would go with whatever unit is used within the problem and stay consistent with it.
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Re: Pressure Units
There is no official unit for this class, but you want to consistent when solving problems. You will normally see problems in bar or atm.
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Re: Pressure Units
I don't believe there is a preferred unit that should be used, but the units you use should be consistent to the units used in the question.
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Re: Pressure Units
You can use either depending on the problem but you must be consistent and cannot use both in the same formula/problem
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Re: Pressure Units
You can use any pressure unit, as long as it matches with the other units in the problem and the formula used, like the R value.
Re: Pressure Units
there is no preference in units, you just need to be consistent. this will let you end up with the correct answer. if you need to use a specific unit, the problem will state that.
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Re: Pressure Units
You can use any pressure unit as long as it matches the other terms or constants that you used.
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Re: Pressure Units
If given a specific pressure unit in a problem, always use that pressure unit, if not, then you can use any pressure unit you like, just remember to be consistent with your units and use the right equations. In chemistry, at least in my experience, I usually use atm, bar, or kPa.
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Re: Pressure Units
Hey !
I think the question will state if the answer has to be given in specific unit.
I think the question will state if the answer has to be given in specific unit.
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Re: Pressure Units
i think they are interchangeable since the units are so similar but i think atm is more commonly used.
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Re: Pressure Units
So far, we have most commonly used atm, bar, and Pascals. If we need to convert between units of pressure, we are usually given the means to do so. The constants/equations sheet already gives us these expressions involving pressure: the ideal gas constant, R, is equal to 8.314 J/(K*mol) = 8.206 x 10-2 (L*atm)/(K*mol) = 8.314 x 10-2 (L*bar)/(K*mol) = 62.364 (L*Torr)/(K*mol); we are also given that 1 atm = 760 Torr.
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Re: Pressure Units
Generally, you should follow whatever units are provided in the problem and will cancel out or provide the answer with the correct units you are looking for. This is usually atm or bar but other units are possible as well.
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Re: Pressure Units
I don't believe that this course has specified preferred units. I typically think we work in ATM, but as long as you are consistent and maintain the given units, you will be fine and likely not expected to transfer between ATM and BAR.
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Re: Pressure Units
There's no official unit of pressure, we use both bar and atm in different problems. Just make sure that you're converting them, bc they shouldn't be used interchangeably.
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Re: Pressure Units
Just use whatever units are given and double check that they line up properly with your constants and formulas.
Re: Pressure Units
You can use either units of pressure, they are very similar to each other, 1 ATM is 1.01 Bar. I prefer to use ATM as I have used that most often before.
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Re: Pressure Units
Hi, I don't believe there's an official unit for pressure, but I would assume that in practice problems or in tests questions the preferred unit would be given.
Re: Pressure Units
I don't believe there is a preferred unit of pressure just make sure that you are consistent in your calculations and use the correct R value.
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Re: Pressure Units
I have noticed that many of the questions that we have been getting have had units in atm. However, if it isn't in atm, then the professor makes sure to be explicit about it.
Re: Pressure Units
As long as the correct R-value is used, there isn't a preferred unit of pressure.
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Re: Pressure Units
I would say that there are no units that are preferred but just make sure that it is consistent with the problem and R value that is being used is also consistent with whatever units you use
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Re: Pressure Units
As long as the question doesn’t specifically ask for the answer in terms of a unit, it’s safe to say that we should stick to the unit given in the problem.
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Re: Pressure Units
It doesn't matter, as long as you're being consistent with the units that you're using in the problem and can manipulate it so that you use the right constants.
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Re: Pressure Units
Use the units you're given, and just make sure you're using whatever unit appropriate in order to get the appropriate result
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Re: Pressure Units
I don't think there is a specific unit for pressure that we need to use. Sometimes, you'll find that the units end up canceling themselves out in the problem, but as far as I know the two most common that we use in problems are atm and bar. It's often helpful to look at the other units in the problem as well to see if you need to cancel anything out.
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