Question

2-Consider the reaction

                            H₂(g)   +    Br₂(g)        2 HBr (g⇌ )

where ΔH^o = -36.4 kJ/mol. In one experiment, equal amounts in moles of H₂(g) and Br₂(g) were mixed in a 2.00 L chamber at 25 ^oC exerting a pressure P = 1.0 atm. After mixture reached equilibrium, partial pressure of H₂ gas P_H2 was measured using high sensitivity HVAC gauge recording, P_H2 = 5x10^-4 Pa.

For this equilibrium reaction, answer the following:

(i)Calculate the total amount n_T of gases initially injected to the chamber, assuming both gases are perfect? deduce the amount of each gas present (i.e. n_H2 and n_Br2 )

(ii)Based on the value of P_H2, find the amount of H₂ left at equilibrium? Hence, deduce the amount of Br₂ left at equilibrium?

(iii)Based on (i) & (ii), find the amount of HBr n_HBr produced? (*You can use the dissociated quantity x terminology to help you get n_HBr ).

(iv) Define K in terms of conc. hence amount n (i.e.*V = 2 L) using the equilibrium reaction above. Substitute for n values determined in (ii)&(iii) to find K? Does the value of K indicate to you that the equilibrium proceeds strongly in the forward or reverse direction?

(v)Define & calculate ΔG^o in terms of K?

*What can you conclude from the value of ΔG^o?

(vi)Define & calculate ΔS^o in terms of ΔG^o and ΔH^o ?

*What can you conclude from the value of ΔS^o?

Answer 1