Process Tech Lab F - Liam and Kaja

(Liam and Kaja) What equation defines the standard enthalpy of reaction ΔHᵣ°?

$\Delta Hr^\circ = \sum ni \Delta H{f,i}^\circ(\text{products}) - \sum nj \Delta H_{f,j}^\circ(\text{reactants})$

(Liam and Kaja) What is the heat capacity correlation used in Part A?

$$C_p = \alpha + \beta T + \gamma T^2$$

(Liam and Kaja) How are Δα, Δβ, and Δγ calculated?

Stoichiometric sum of product coefficients minus reactant coefficients.

(Liam and Kaja) What equation gives ΔHᵣ at any temperature T?

$\Delta H{r,T}^\circ = \Delta H{r,298}^\circ$

• $\Delta\alpha (T - 298)$

• $\frac{\Delta\beta}{2}(T^2 - 298^2)$

• $\frac{\Delta\gamma}{3}(T^3 - 298^3)$

(Liam and Kaja) Why does ΔHᵣ vary with temperature

Because species heat capacities vary with temperature.

(Liam and Kaja) What is the goal of Part A in Lab F?

Use thermodynamic data and Cp correlations to compute ΔHᵣ over 30–1000 °C.

(Liam and Kaja) What must be plotted for Part A?

ΔHᵣ vs temperature (°C or K).

(Kaja) What is the stoichiometry for R1?

CH₄ + H₂O → CO + 3H₂

(Kaja) What is the reaction type for R1 in Part 2?

Reaction A (A + B → 2M + 2N).

(Kaja) What is the rate law for R1 in Part 2?

$$-r_A = k[A]^2$$

(Kaja) What is k for R1?

k = 0.03 (units: L mol⁻¹ s⁻¹).

(Kaja) What is [A]₀ for R1?

[A]₀ = 0.08 M.

(Kaja) What is the target conversion Xₐ for R1?

Xₐ = 0.8

(Kaja) What is the molecular change Δn for R1?

Products: 4 mol gas; Reactants: 2 mol gas → Δn = +2.

(Liam) What is the stoichiometry for R5?

4 CH₄ + O₂ → 2 C₂H₆ + 2 H₂O

(Liam) What is the Part 2 reaction type?

Reaction A (2A + B → 2M).

(Liam) What is the rate law for R5?

$$-r_A = k[A]^{0.5}$$

(Liam) What is k for R5?

k = 3.6

(Liam) What is [A]₀ for R5?

[A]₀ = 0.08 M.

(Liam) What is the target conversion Xₐ?

Xₐ = 0.4

(Liam) What is Δn for R5?

Reactants: 5 mol gas
Products: 4 mol gas
Δn = −1