Tutorial 3 solutions

1. Tutorial 3 solutions Lecturer: Miss Anis Atikah Ahmad Tel: +604 976 3245 Email: anisatikah@unimap.edu.my

2. Questions • Write the rate laws for the following reactions assuming each reaction follows an elementary rate laws. • C2H6 → C2H4 + H2 • (CH3)3COOC(CH3)3 ⇌ C2H6 + 2CH3COCH3 • Write the rate law for the reaction: 2A + B → C if the reaction • is second order in B and overall third order, • is zero order in A and first order in B • is zero order in both A and B • is first order in A and overall zero order

3. The formation of ortho-nitroanilineis formed from the reaction of ortho-nitrochlorobenzene(ONCB) and aqueous ammonia. The liquid-phase reaction is first order in both ONCB and ammonia with k= 0.0017 m3/kmol-min at 188°C with E = 11,273 cal/mol. The initial entering concentration of ONCB and ammonia are 1.8 kmol/m3 and 6.6 kmol/m3 respectively. • Write the rate law for the rate of disappearance of ONCB in terms of concentration. • Set up stoichiometric table for this reaction for a flow system. • Explain how part (a) and (b) would be different for a batch system. • Write –rAsolely as a function of conversion. • What is the initial rate of reaction (X=0) at 188°C and at 25°C? • What is the rate of reaction when X = 0.9 at 188°C and at 25°C? • What would be the corresponding CSTR volume at 25°C to achieve 90% conversion at 188°C for a feed rate of 2 dm3/min

4. Write the rate laws for the following reactions assuming each reaction follows an elementary rate laws. • C2H6 → C2H4 + H2 • (CH3)3COOC(CH3)3 ⇌ C2H6 + 2CH3COCH3 Question (1) (a) (b) • C2H6 → C2H4 + H2 • A → B + C • (CH3)3COOC(CH3)3 ⇌ C2H6 + 2CH3COCH3 • A ⇌ B + 2C

5. Write the rate law for the reaction: 2A + B → C if the reaction • is second order in B and overall third order • is zero order in A and first order in B • is zero order in both A and B • is first order in A and overall zero order Question (2) (a) (b) (c) (d)

6. Question (3)(a) The formation of ortho-nitroanilineis formed from the reaction of ortho-nitrochlorobenzene(ONCB) and aqueous ammonia. The liquid-phase reaction is first order in both ONCB and ammonia with k= 0.0017 m3/kmol-min at 188°C with E = 11,273 cal/mol. The initial entering concentration of ONCB and ammonia are 1.8 kmol/m3 and 6.6 kmol/m3 respectively. • Write the rate law for the rate of disappearance of ONCB in terms of concentration. Let A = ONCB, B = NH3, C = Nitroaniline , D = NH4Cl

7. Question (3)(b) A + 2B → C + D • Set up stoichiometric table for this reaction for a flow system

8. Question (3)(c) • Explain how part (a) and (b) would be different for a batch system For batch system,

9. Question (3)(d) • Write –rAsolely as a function of conversion. For liquid phase rxn, υ= υ0

10. Question (3)(d) Substituting the concentration of A & B;

11. Question (3)(e) ---(1) • What is the initial rate of reaction (X=0) at 188°C and at 25°C i) At T= 188°C, k =0.017m3/kmol-min Substituting X=0 and k =0.017m3/kmol-min into (1);

12. Question (3)(e) ---(1) • What is the initial rate of reaction (X=0) at 188°C and at 25°C ii) At T= 25°C (298.15 K), k =? m3/kmol-min Find k at T =25°C first k at initial T is k at any temperature is Taking the ratio;

13. Question (3)(e) ---(1) • What is the initial rate of reaction (X=0) at 188°C and at 25°C ii) Now we know that, at T= 25°C (298.15 K), k = 2.039 x 10-6 m3/kmol-min Therefore, we can calculate –rA at 25° by susbtituting k= 2.039 x 10-6m3/kmol-min, and X = 0 in eq (1).

14. Question (3)(f) ---(1) • What is the rate of reaction when X = 0.9 at 188°C and at 25°C? (i) At T= 188°C, k =0.0017m3/kmol-min Substituting X=0.9 and k =0.017m3/kmol-min into (1);

15. Question (3)(f) ---(1) • What is the rate of reaction when X = 0.9 at 188°C and at 25°C? (ii) From part (e) when T= 25°C, k = 2.039 x 10-6 m3/kmol-min Substituting X=0.9 and k = k = 2.039 x 10-6 m3/kmol-min into (1);

16. Question (3)(g) • What would be the corresponding CSTR volume at 25°C to achieve 90% conversion at 188°C for a feed rate of 2 dm3/min? Substituting the value of CA0, υ0 and –rA(at 288°C & X=0.9);