Chemistry · May / June 2023 · Paper 42 · Question 3
0620
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The question as text
Over 200 million tonnes of sulfuric acid are manufactured every year.
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3(a)[1]
contact (process)
3(b)(i)[2]
M1 burning sulfur (in air)
M2 Roasting sulfide ores (in air)
3(b)(ii)[2]
M1 the rate of forward reaction equals (the rate of the) reverse reaction
M2 concentrations of reactants and products are constant
3(b)(iii)[3]
450 (oC)
200 (kPa)
vanadium(V) oxide
3(b)(iv)[4]
increases
increases
increase
no change
3(b)(v)[3]
M1 kinetic energy of particles decreases
M2 frequency of collisions between particles decreases
M3 lower percentage / proportion / fraction of collisions / particles have energy greater than / qual to activation energy OR
fewer of the collisions / particles have energy greater than / equal to activation energy
M2 S + (4 × –2) = –2 ∴ S = + 6
3(c)[2]
M1 4 × −2 or −8
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