contact process

Question 1

cp stage one

Answer 1

sulfur is burned in air to form sulfur dioxide

S(s) + O2(g) –> SO2(g)

Question 2

cp stage 2

Answer 2

sulfur dioxide is oxidised by catalyst vanadium to produce sulfur trioxide
right- exo, left-endo
low temp-slow, high temp- endo- moves to left so low yield
low pressure- low yield, more moles, high pressure-costly, energy consuming, safety hazard

2SO2(g) + O2(g) 2SO3(g)

Question 3

cp stage 3

Answer 3

sulfur trioxide dissolved in concentrated (98% 18M) sulfuric acid to form oleum- disulfuric (pyrosulfuric) acid

SO3(g) +H2SO4(l) –> H2S2O7(l)

Question 4

cp stage 4

Answer 4

oleum diluted with water to form concentrated sulfuric acid

H2S2O7(l) + H2O(l) –> 2H2SO4(l)

Question 5

conditions for contact process

Answer 5

450*
2-6 atmospheres
vanadium(v) oxide catalyst

Question 6

what is sulfuric acid used for

Answer 6

fertilisers, paints, detergent, explosives

Question 7

raw materials used in the contact process

Answer 7

dried sulfur
air
water