In economic terms, it is essential to achieve - in a safe environment -
the maximum yield in any given industrial process in the minimum time. 
Not surprisingly, therefore, the variables which affect the yield and
the rate of a reversible reaction are important considerations in plant
design; and, for example, certainly would have been in the optimization
of one industrial method of manufacturing ethanoic acid, which involves 
the catalyzed, gas-phase reaction between methanol and carbon monoxide.

[Scene.  A tea-party in the plush boardroom of Hydragyrum Chapelier
Vinaigrette (a small company which, most curiously, manufactures hats
and ethanoic acid); the chairman's name is Monsieur Oliver Scrooge.]
O. Scrooge:  We cannot rest on our laurels of the past.  So, I want 
             more, and I want it faster!  [The board members ignore
             this party pooper.]  Otherwise, ... each of you will be 
             collecting your Christmas present from the Government.
             [With this veiled threat, Les Femmes are all attention.]
La Vitesse:  Well, ... a catalyst would increase the rate.  However,
             it is a compound of a precious metal: ... so there would
             be a major capital cost.  Nevertheless, we can re-use
             the catalyst ... providing, of course, we minimize the
             introduction of inhibitors into the reaction vessels.
O. Scrooge:  Will it increase the yield?  [His tone is hopeful.]
La Vitesse:  Certainly not!  [S. looks glum.]  No catalyst changes 
             the position of equilibrium.  On the other hand, without
             a catalyst, we would definitely need to use much higher 
             temperatures: ... so, indirectly, it would reduce costs.
La Chaleur:  True, though a high temperature would increase the rate.
O. Scrooge:  Yes, ... but will a high temperature increase the yield?
La Chaleur:  Certainly not!  Do pay attention!  The reaction is
             exothermic.  [S. looks chastened and even more glum.]
La Pression: A high pressure would also increase the rate ... though,
             again, with increased operating costs.
O. Scrooge:  Yes, yes, ... [His tone is weary.] ... but will a high 
             pressure increase the yield? 
La Pression: Certainly!  [S. perks up.]  To echo La Chaleur, do pay
             attention!  Note that there are fewer moles of gas on
             the product side of the equation ... well, none in fact.
O. Scrooge:  How absolutely splendid!  I suggest that we should be
             miserly with the catalyst, use a lowish temperature, and 
             boost the pressure massively.  [His tone is bullish.]
La Securité: No, ... not necessarily.  I must urge caution.  Reaction
             vessels strong enough to withstand very high pressures 
             are exceedingly expensive.  The safety of our workers 
             and the general public is paramount!
O. Scrooge:  Oh dear, are all females of the species this sensible?  
             [His tone is ambiguous, perhaps even patronizing.]
La Securité: Certainly: ... well, most of the time.  However, we will
             suspend judgement on your future, ... [Les Femmes glance
             pointedly at the sharp stiletto heels on their shoes.]
             ... until after we have received our Christmas bonuses.
O. Scrooge:  [He picks up a telephone.]  Bob, is that you?  Please
             come back ...

1.  One (no longer used) method of obtaining hydrogen chloride involved 
the copper(II)-catalyzed reduction of chlorine;
(a) Complete the Table below using these bond energies (in kJ mol-¹):
463 (O-H), 243 (Cl-Cl), 432 (H-Cl), and 497 (O=O).
  Bonds broken  
 Energy absorbed 
   / kJ mol-¹
  Bonds formed  
 Energy released 
   / kJ mol-¹
          Total =      
          Total =      
Calculate the heat energy change (DH) for the above reaction. _________
(b) Explain the purpose of the broken brick. __________________________
(c) Complete and label this energy level diagram for the reaction.
           Energy                 ___
           ___________________ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
                            Path of reaction
(d) Explain the effects, on the rate of this reaction and the yield of
hydrogen chloride, of using: 
A high pressure _______________________________________________________
A high temperature ____________________________________________________
2.  In industry, hydrogen chloride is usually obtained as a co-product
of the manufacture of chlorinated hydrocarbons; e.g.,
(a) Suggest the rôle of light in this (substitution) reaction. ________
(b) State briefly why the use of a high pressure in this reaction would 
not increase the yield of products. ___________________________________
(c) Suggest one advantage that this industrial method has over that 
described in 1. _______________________________________________________
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