Calculate the amount of energy in the form of heat that is produced when a volume of 3.56 L of SO2(g) is converted to 3.56 L of SO3(g) according to this process at a constant pressure and temperature of 1.00 bar and 25.0 °C. Assume ideal gas behavior.
Actually I solved it - and just to clarify what Dr. bob was doing:
dHrxn = (n*dH SO3) - (n*dH SO2) where n is equal to 2 based on the stoichiometric equation 2SO2 + O2 ==> 2SO3
Indeed, Find dHf SO3 and dHf SO2 in tables in your text or notes.
Then, the number of moles of SO3(g) produced is determined from the ideal gas law.
So Convert 3.56L to mols = n using PV=nRT or n=PV/RT and use the constant R = 0.08315 in L*bar/mol/k
The chemical equation as given represents the production of two moles of SO3(g), so the energy as heat that evolved is
dH = (mols of SO3 calculated just before) x (dHrxn / 2 mol SO3)
dr bob is not actually dr bob.. people r using his names to give out incorrect answers.
Dr. Bob,
I don't think this is the answer. It's close, but I think there is another step.
Could you elaborate on your answer to make it more clear?
To calculate the amount of energy in the form of heat produced during the conversion of SO2(g) to SO3(g), we first need to determine the change in enthalpy (∆H) for the given reaction. Enthalpy is a measure of the heat absorbed or released in a chemical reaction at constant pressure.
The balanced chemical equation for the reaction is:
2 SO2(g) + O2(g) → 2 SO3(g)
From this equation, we can see that 2 moles of SO2 react to produce 2 moles of SO3. Therefore, the molar ratio of SO2 to SO3 is 2:2 or 1:1.
To determine ∆H for the reaction, we can use thermochemical data. The standard enthalpy change (∆H°) for the reaction can be obtained from reference sources or calculated using bond enthalpies, which represent the energy required to break or form chemical bonds.
Assuming ideal gas behavior, we can use the ideal gas equation to relate the given conditions to the moles of gas involved. The ideal gas equation is:
PV = nRT
P = pressure (in this case, 1.00 bar)
V = volume (in this case, 3.56 L)
n = number of moles
R = ideal gas constant (0.0821 L·atm/(mol·K))
T = temperature (in this case, 25.0 °C or 298.15 K)
Let's start by calculating the moles of SO2 using the ideal gas equation:
n(SO2) = (P * V) / (R * T)
= (1.00 bar * 3.56 L) / (0.0821 L·atm/(mol·K) * 298.15 K)
Convert pressure from bar to atm:
1 bar = 0.9869 atm
n(SO2) ≈ (0.9869 atm * 3.56 L) / (0.0821 L·atm/(mol·K) * 298.15 K)
Once you calculate the value for n(SO2), you'll have the number of moles of SO2.
Since the molar ratio of SO2 to SO3 is 1:1, the moles of SO3 produced will also be equal to n(SO2).
Now, to determine the amount of energy in the form of heat produced, we multiply the moles of SO2 (or SO3) by the ∆H° for the reaction.
q = ∆H° * n
The unit of ∆H° may vary depending on the reference source used. Make sure to check the proper unit and convert it if necessary.
By calculating the moles of SO2 and multiplying by the appropriate ∆H° value, you'll be able to find the amount of energy in the form of heat produced when the given volume of SO2 is converted to SO3.
2SO2 + O2 ==> 2SO3
Convert 3.56L to mols = n. Then
dHrxn = (n*dH SO3) - (n*dH SO2)
Find dHf SO3 and dHf SO2 in tables in your text or notes.