Calculate the partial pressure of monatomic hydrogen in hydrogen gas at 2000 K and 1 atm pressure.
Given:
(i) For ½ H2 ï‚® H, ï�„Ho298=217,990 J; ï�„So298=49.35 J/K.
(ii) Assume that the heat capacity of monatomic gas to be 3/2R
(iii)The heat capacity of H2 assume to be 31 J/(mol K)
For 1/2 H2 -> H, DeltaHo298=217,990 J; DeltaSo298=49.35 J/K
Nb: DeltaHo298=DeltaH standard at 298K
DeltaSo298=DeltaS standard at 298K
Guys, pliz help me, I need to get general ideas of how to do this.
thank you so much.
Do we have to find deltaH and deltaS at 2000K, and after that , find deltaG by using this formula deltaG=deltaH-T*deltaS
.
Next, deltaG=-RT*lnKp
where Kp=P(H)/((p(h2))^(1/2))
If this is correct, what is p(h2)/ partial pressure of hydrogen? so that we can find partial pressure for the monatomic hydrogen?
i got my other eyes on you
-mats-
To calculate the partial pressure of monatomic hydrogen (H) in hydrogen gas (H2) at 2000 K and 1 atm pressure, we can use the concept of Gibbs free energy (ΔG). The equation to calculate ΔG is:
ΔG = ΔH - TΔS
Where:
ΔG = change in Gibbs free energy
ΔH = change in enthalpy
ΔS = change in entropy
T = temperature in Kelvin
In this case, we want to find the partial pressure of H, which means we need to calculate the ΔG of the reaction H2 → 2H.
Step 1: Calculate ΔH
Given that ΔHo298 for the reaction ½ H2 → H is 217,990 J/mol, we can convert this to ΔH2000 using the equation:
ΔH2000 = ΔHo298 + ∫CpdT
Where:
Cp = heat capacity at constant pressure
dT = change in temperature
Since the heat capacity of monatomic gas is given as 3/2R, we substitute the values:
ΔH2000 = ΔHo298 + (3/2R) * (T2000 - T298)
Step 2: Calculate ΔS
Given that ΔSo298 for the reaction ½ H2 → H is 49.35 J/(mol K), we can use the same equation as above to calculate ΔS2000:
ΔS2000 = ΔSo298 + Cp * ln(T2000/T298)
Where:
ln = natural logarithm
Step 3: Calculate ΔG
Now that we have ΔH2000 and ΔS2000, we can calculate ΔG2000 using the formula mentioned earlier:
ΔG2000 = ΔH2000 - T2000ΔS2000
Step 4: Calculate the partial pressure of H
Finally, we can calculate the partial pressure of monatomic hydrogen (H) using the equation:
p(H) = p(H2) * exp(-ΔG2000 / (RT))
Where:
p(H) = partial pressure of monatomic hydrogen
p(H2) = total pressure of hydrogen gas (given as 1 atm)
R = ideal gas constant (8.314 J/(mol K))
T = temperature in Kelvin (2000 K)
Substituting the values, you can calculate the partial pressure of monatomic hydrogen in hydrogen gas at 2000 K and 1 atm pressure.