<u>Step 1:</u>
ok we have to use the formula PV=nRT
p=Pressure (must be converted to atm)= 780 mmHg
1 amt= 760 mmHg use this as a conversion factor
780 mmHg (1 atm/760 mmHg)= 1.026
V= Volume= 5.00 mL = o.5 L
n=number of moles which we have to find first
R= 0.0821
T(convert to Kelvins by adding 273.15 to the celsius temperature)= 135 C + 273.15= 408.15 k
Now plug in->
(1.026 atm)(o.5 L)= n(0.0821)(408.15 K)
(1.026 atm)(0.5 L)= n(33.509115)
(0.513)= n(33.509115)
n(number of moles)= 0.01532 mol
Now we have to convert to moles using Avagodro's number which states that 1 mol = 6.022 x 10^23 molecules or atoms
So 0.01532 mol (6.022 x 10^23 number of molesules)/ (1 mol) = 9.225704 x 10^21 = 9.226 x 10^21 colecules
Step 2
You must transfer pressure into pascals, 780 mm Hg = 103991 Pa
135*C = 408.15 k
then from the equation pV = nRt
n = pV / RT (T in Kelvins, V in M^3)
n = 103991 x 500 x 10^-6 / (8.314 x 408.15)= 0.015322 moles of N2
1 mol of everything is 6.022 x 10^23 particles, so 0.15322 moles is 0.15322 x 6.022 x 10^23 = 9.2269084 x 10^21 molecules
Explanation:
Hope this helps :)
