ES 7

Question 1

why was the deacon process created

Answer 1

to break down highly toxic hydrogen chloride gas released during the production of alkalis

Question 2

what was the process of the old deacon process

Answer 2

hydrogen chloride was mixed with oxygen over and passed over a catalyst
chlorine and steam are the products
4HCl (aq) + O2 (g) —- 2Cl2 (g) + 2H2O (g)

Question 3

what are the best conditions to optimise yield of chlorine and where does equilibrium need to be positioned

Answer 3

• high pressure
• low temperature
• excess oxygen
  equilibrium needs to be positioned to the right (products)

Question 4

what are the features of deacon process today

Answer 4

• uses lower temperatures at a lower cost
• produces almost pure chlorine

Question 5

what are the two steps in the deacon process today and what are the benefits

Answer 5

step one - CH2==CH2 (g) + CL2 —- CH2ClCH2Cl (l)
step two - CH2ClCH2Cl (l) —-CH2==CHCl (g) + HCl (g)
HCl produced in step 2 can be converted back into Cl2 and used as a feedstock for step 1
- cheaper than producing Cl2 from electrolysis
- transport hazard of liquid chlorine is eliminated

Question 6

what is the effect of pressure on the position of equilibrium#
CHANGING TOTAL PRESSUE OF SYSTEM WILL ONLY HAVE AN EFFECT ON EQUILIBRIUM IF THERE ARE GASES PRESENT

Answer 6

increasing pressure moves the equilibrium to the side of the equation with fewer gas molecules as this reduces the pressure
decreasing pressure moves the equilibrium to the side of the equation with more gas molecules as this increases the pressure

Question 7

what effect does a catalyst have on the position of equilibrium

Answer 7

a catalyst does not change the position of equilibrium
however it does increase the rate that the equilibrium is reached
a catalyst will increase both the forward and backwards reaction equally