Question

What pH is needed to produce this value of Q (4.6*10^-26) if the concentration and pressure values are

[Br2]=3.00×10−4M,

[Br−]=11.25M,

[SO42−]=9.70M,

PSO2=1.00×10−5atm

Answer 1

SO4^2- (aq) + 4H^+ (aq) + 2Br^- (aq) -------------> Br2(aq) + SO2(g) + 2H2O(l)

Q   = PSO2*[Br2]/[SO4^2-][H^+]^4[Br^-]^2

[Br2]=3.00×10−4M,

[Br−]=11.25M,

[SO42−]=9.70M,

PSO2=1.00×10−5atm

Q = 4.6*10^-26

Q   = PSO2*[Br2]/[SO4^2-][H^+]^4[Br^-]^2

4.6*10^-26   = 1*10^-5 *3*10^-4/9.7*[H^+]^4*11.25

[H^+]^4         = 1*10^-5 *3*10^-4/9.7*4.6*10^-26*11.25

[H^+]^4        = 5.97*10^14 M

[H^+]             = 4.94*10^3M

PH = -log[H^+]

        = -log4.94*10^3

        = -3.6937>>>>>answer