[samiam]

we only did one example of this type of question in lecture.
and it is not important for now but i'm still curious of how this equation works, all we really need to know is how to plug and chug.
STP= 0 atm and 273.15 K or 0 degree celsius--> what is the point of STP, does it even influence or effect equation when entering in values.
1 atmp= 101.3 kpa=760 Torr...I Guess you would use this to convert torr to kpa or atm and input it into the formula.
- All I Know is if you are given temp in celsius you would convert to kelvins and input it into the formula.


and there is three constants values R= 8.314 J/mol *K--> not sure when to use this we never talk about joules in the course.
R= 8.314 kpa L/mol*k--> I guess you use this when you are given pressure in kpa
R= 0.0821 atm L/mol*k  --> use this when you are given pressure in atm

[UG]

Just a slight correction, standard pressure = 1 atm not 0.
For the gas constant R= 8.314 J/mol K, the units are derived as such:
Rearrange the ideal gas law until you isolate R, R = PV/nT. If you're given the volume in m³ and the pressure in Pa, then the units would be (Pa x m³)/(mol x K) = the unit for R.
Now 1 pascal is = 1 N m^-2 so then we have (1 N m^-2 x m³)/(mol x K) = the unit for R
However, 1 N = 1 kg m s^-2
So now we end up with (kg m s^-2 x m^-2 x m³)/(mol x K) = the unit for R
Simplifying, we get (kg m² s^-2)/(mol x K) = the unit for R
Conveniently, 1 J = 1 kg m² s^-2
So we have (J)/(mol x K) = the unit for R which is how they got R = 8.314 J/mol K

[Yggdrasil]

we only did one example of this type of question in lecture.
and it is not important for now but i'm still curious of how this equation works, all we really need to know is how to plug and chug.
STP= 0 atm and 273.15 K or 0 degree celsius--> what is the point of STP, does it even influence or effect equation when entering in values.

The values of STP do not affect the equation, but they are good to know if a problem refers to STP.  I will also note as UG has said that STP is 1 atm pressure, not 0.

1 atmp= 101.3 kpa=760 Torr...I Guess you would use this to convert torr to kpa or atm and input it into the formula.

Correct.

- All I Know is if you are given temp in celsius you would convert to kelvins and input it into the formula.

Correct.  This is necessary because Kelvin is an absolute temperature scale (0 K refers to zero temperature [i.e. no available thermal energy]) whereas 0^oC does not correspond to zero temperature.

and there is three constants values R= 8.314 J/mol *K--> not sure when to use this we never talk about joules in the course.
R= 8.314 kpa L/mol*k--> I guess you use this when you are given pressure in kpa
R= 0.0821 atm L/mol*k  --> use this when you are given pressure in atm

The main values of R that you will use are the versions in units of kPa L mol^-1 K^-1 and atm L mol^-1 K^-1.  The version in units of J mol^-1 K^-1 is useful for many thermodynamic calculations (for example, when determining equilibrium constants from changes in Gibbs free energy).  Note that using the pressure conversions above, you can see that 8.314 kPa L mol^-1 K^-1 = 0.0821 atm L mol^-1 K^-1.

[billnotgatez]

<rant mode on>

I am hesitant to mention this but I will anyway. The original person who posted may want to ignore my comments.

All values in the ideal gas equation must be converted to absolutes. So for instance 273.15 K is the absolute and 0 C is not the absolute temperature. I can not think of a way that you can have a volume that is not absolute. But, I have had problems presented to me that the pressure was not stated as and absolute. I can remember having to convert PSI to APSI (absolute PSI) and then convert to metric or ATM. So when I saw the original posting having 0 ATM, I assumed that it was not absolute and had to be changed to 1 AATM  (absolute ATM)  for STP. It never occurred to me that the post was a typo. Having said this it seems every post I have seen in the past ATM is assumed to be AATM.

This is the stuff that drives me crazy since STP and ATM are something one is expected to know even though it depends on who you are dealing with when answering the question. I personally think it is poor form to use STP rather than state the temperature and pressure, and also not state pressure as absolute. Many gages do not measure absolute.

<rant mode off>