A sample of nitrogen gas is confined in a 8.494 L container at 2.643 x 102 torr and 50 oC. How many moles of gas are present in the sample? So I thought I set this problem up right and when I type the answer into CALM my answer is incorrect. This is what I did:
PV=nRT (2.643 x 102 torr)(8.494 L)=n(0.0821)(323.15 degrees Kelvin)
I divided the numbers to get "n" alone and my answer was 84.6 moles
Please explain what I am doing wrong! Thank you!
either convert Torrs or use
R = 62.4 Liter Torr/ ( deg K mol)
I will try this, thank you!
when in danger or in doubt about units, type for example:
gas constant Torrs liters
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To determine the number of moles of gas present in the sample, you correctly used the ideal gas law equation: PV = nRT. However, there seems to be an error in the conversion of temperature from degrees Celsius to Kelvin.
The correct conversion from Celsius to Kelvin is to add 273.15 to the Celsius temperature. In this case, the temperature is given as 50 oC, so it should be converted to Kelvin as follows:
Temperature in Kelvin = 50 + 273.15 = 323.15 K
Now, let's substitute the correct values into the ideal gas law equation:
(P)(V) = (n)(R)(T)
(2.643 x 102 torr)(8.494 L) = (n)(0.0821 L∙atm/mol∙K)(323.15 K)
Simplifying the equation gives:
224.265 L∙torr = 0.0821 n∙K
Next, you need to convert torr to atm, as the value of R (the ideal gas constant) is in units of liter-atmospheres per mole Kelvin.
1 atm = 760 torr
So, divide both sides of the equation by 760 to convert torr to atm:
224.265 L∙torr / 760 = 0.0821 n∙K
0.295 atm∙L = 0.0821 n∙K
Finally, divide both sides of the equation by 0.0821 to solve for n (the number of moles):
0.295 atm∙L / 0.0821 n∙K = 1
n = 0.295 atm∙L / 0.0821 n∙K
n ≈ 3.59 moles
So, the correct number of moles of gas present in the sample is approximately 3.59 moles, not 84.6 moles.