what is the gas constant (R) for mm Hg?
8.31 is for atm
.08206 is for kPa
right?
You have them reversed.
0.08205 for atm
8.31 for kPa.
Then my teacher is messed up. So, for mm Hg it would be...?
By the way, Happy Halloween!!!!!
If you have pressure listed in mm mercury, change to atm by dividing by 760 mm/1 atm, then use R as 0.08206 L*atm/mol*K. If pressure is in kPa, use R as 8.3145 J/mol*K (kPa*L/mol*K).
Pressure in mm Hg may be changed to kPa by multiplying mm Hg x 0.13332 and using R of 8.1345 BUT I've not seen that done. You can try this yourself.
PV = nRT
Let's have P = 760 mm, V = 22.415 L, n = 1, R =?? and T = 273.15 K.
Solve for R.
R = PV/nT = (760/760)*22.415/1*273.15 = 0.08206
Let P = 101.325 kPa, V = 22.415 L, n = 1, R = ??, and T = 273.15 K.
R = 101.325*22.415/1*273.15 = 8.315
Let P = 760 mm, V = 22.415 L, n = 1, R = ?? and T = 273.15 K.
R = 760*22.415*0.13332/1*273.15 = 8.315
Here is a site that talks a little more about it but the conversion from mm Hg to kPa is not listed. http://en.wikipedia.org/wiki/Gas_constant
Yes, you are correct. The gas constant (R) has different values depending on the units used for pressure.
The gas constant for pressure measured in atmospheres (atm) is 8.31 J/(mol·K).
The gas constant for pressure measured in kilopascals (kPa) is 0.08206 L·atm/(mol·K).
However, to convert the pressure unit to millimeters of mercury (mm Hg), you need to use the following conversion factors:
1 atm = 760 mm Hg
1 kPa = 7.5 mm Hg (approximately)
So, to find the gas constant for mm Hg, you can either convert the value of R in atm or in kPa to mm Hg using the appropriate conversion factor.
To convert the value of R from 8.31 J/(mol·K) to mm Hg, you can use the fact that 1 J = 0.0075 mm Hg. Therefore, the gas constant for mm Hg is approximately 62.2 mm Hg/(mol·K) (8.31 * 0.0075).
To convert the value of R from 0.08206 L·atm/(mol·K) to mm Hg, you can use the fact that 1 atm = 760 mm Hg. Therefore, the gas constant for mm Hg is approximately 62.4 mm Hg/(mol·K) (0.08206 * 760).
So, the gas constant (R) for mm Hg is approximately 62.2 mm Hg/(mol·K) if you convert it from the value in atm, or approximately 62.4 mm Hg/(mol·K) if you convert it from the value in kPa.