The Student Room Group

Pls help with AS chemistry-Le Chatelier's Principle, Contact Process

If (delta)H for the contact process were +98 KJ/mol instead of -98 KJ/mol, which of the following conditions might it be sensible to employ? Give reasons for any differences between these conditions and those which are actually used in the contact process.
X=1000 K, 2 atm, no catalyst.
Y= 400 K, 10 atm, V2O5 catalyst
Z= 1000 K, 10 atm, V2O5 catalyst


Use Le Chatelier’s Principle to suggest the conditions of temperature and pressure which would ensure a good yield of synthesis gas. (4 marks)

Ethanol may be manufactured by the hydration of ethene. State an explain the effect on the position of equilibrium in this reaction of : i) increasing the temperature (2 marks), ii) increasing the pressure (2 marks), iii) using a catalyst (2 marks).
Considering the following equation
2SO2 (g)+O2 (g)2SO3 (g)2SO_2 \ _{(g)} + O_2 \ _{(g)} \begin{array}{c}\rightharpoonup\\ \leftharpoondown\end{array} 2SO_3 \ _{(g)}


If it's an endothermic reaction (ie +98 kJ/mol) then equilibrium will shift to the endothermic reaction upon increasing temperature. So if the reaction was +98, then increasing temperature will yield you more products.

Increasing the pressure, whether it is endothermic or exothermic, will shift equilibrium to the sides of fewer moles of gas. In this case, an increase in pressure would shift equilibrium to the right hand side, yielding more products.

The catalyst does not affect equilibrium position, but it allows the reaction to reach equilibrium quicker, increasing reaction rate.

Read here for information: http://www.chemguide.co.uk/physical/equilibria/contact.html
*girlie*

Ethanol may be manufactured by the hydration of ethene. State an explain the effect on the position of equilibrium in this reaction of : i) increasing the temperature (2 marks), ii) increasing the pressure (2 marks), iii) using a catalyst (2 marks).

Considering,
http://www.chemguide.co.uk/physical/equilibria/ethanoleq.gif

i) As the forward reaction is exothermic, increasing temperature will shift equilibrium to the left hand side (side of reactants) because it favours the endothermic reaction.

ii) increasing pressure will shift equilibrium to side of fewer moles of gas - in this case, the right hand side.

iii) Catalyst has no effect on equilibrium position.


Further info: http://www.chemguide.co.uk/physical/equilibria/ethanol.html#top

Latest