How many times it is necessary to increase the concentration of the hydrogen sulfide, to the reaction rate 2Н2S(g) + SО2(g) = 2S(s) + 2Н2О(g) risen in the 9 times ?

given:
υ>in 9 times
find:
Δс(Н2S) - ?
Solution:
υ = k•с(Н2S)2 • с(SO2)
υ = k•с(Н2S)2 • с(SO2)
υ = 9 mol/lit • с (by condition problem)
1) с2(Н2S) = с1(Н2S) • х2
2) с2(SО2) = с1(SО2)
3) 9 mol/lit  = k • х2
х = 3 mol/lit•s.
Answer:  to increase the rate of this reaction is 9 times necessary to increase the concentration of hydrogen sulfide in 3 times.