How many molecules are there in 985 mL of nitrogen at 0.0 degrees C and 1.00x10^-6 mmHg?
3.50 molecules
This is my work:
985mLN / 1000 = .985 L
0.0 degrees C + 273 = 273 K
1.00x10^-6 mmHg / 760 mmHg = 1.32 atm
1.32 atm x .985 L = n ( .08206 Latm / molK)x273K
n = .0580 moles x 6.022x10^23 = 3.50 x 10^23 molecules.
Ok thanks
The digits are close but the 10^? is missing.
3.50x10^23 molecules
I don't like that answer either. Post your work and let me find the error.
By the way, the 12 atm to 25 atm problem below is OK but the site will not let me post an OK.
Ok thanks!
To determine the number of molecules in a given volume of gas, you can use the ideal gas law, which states:
PV = nRT
Where:
P = pressure of the gas (in this case, 1.00x10^-6 mmHg)
V = volume of the gas (985 mL = 0.985 L)
n = number of moles of the gas (what we want to find)
R = the ideal gas constant (0.0821 L·atm/mol·K)
T = temperature in Kelvin (0.0 degrees C = 273.15 K)
First, convert the pressure from mmHg to atm by dividing by 760 (since 1 atm = 760 mmHg). So, the pressure becomes 1.31579x10^-9 atm.
Next, convert the volume from mL to L by dividing by 1000. The volume becomes 0.985 L.
Substituting these values into the equation, we get:
(1.31579x10^-9 atm) * (0.985 L) = n * (0.0821 L·atm/mol·K) * (273.15 K)
Simplifying this equation gives:
1.29224x10^-9 = n * 22.4144
Now, solve for n (the number of moles of nitrogen):
n = 1.29224x10^-9 / 22.4144
n ≈ 5.77x10^-11 mol
To convert moles to molecules, you need to multiply the number of moles by Avogadro's number (6.022x10^23 mol^-1). So, the number of molecules is:
(5.77x10^-11 mol) * (6.022x10^23 mol^-1) ≈ 3.47x10^13 molecules
Therefore, there are approximately 3.47x10^13 molecules in 985 mL of nitrogen at 0.0 degrees C and 1.00x10^-6 mmHg.
985mLN / 1000 = .985 L
0.0 degrees C + 273 = 273 K
1.00x10^-6 mmHg / 760 mmHg = 1.32 atm YOU forgot the 10^-6
1.32 atm x .985 L = n ( .08206 Latm / molK)x273K
n = .0580 moles x 6.022x10^23 = 3.50 x 10^23 molecules.
For digits I obtained 3.48; the difference is that you rounded the 1.315 to 1.32 while I left all of that in the calculator and made all of it as one calculation. It appears you made three calculations.
Also 1.00/760 is not 1.32 but 1.32E-3.
Thus 1E-6/760 = 1.32E-9 I think.