Electrochemistry Exercise: Normal Potential of a Reaction

[D_Tr]

Homework Statement

Calculate the normal potential at 25 °C for the reaction:

HA(aq) + e^- → A^-(aq) + 1/2H₂(g)

if the dissociation constant of HA is equal to 3.3*10^-4

Homework Equations

ΔG° = -RTlnK ⇔ -ΔG°/nF = RT/(nF)lnK ⇔ E° = RT/(nF)lnK

The Attempt at a Solution

Just plugging in the numbers gives the answer E°=-0.206V
However, the answer key of the textbook disagrees on the sign... Am I overlooking something or is it just a typo? I can't imagine what my mistake could be...

 

[Borek]

Typo for me. But I am known to be occasionally wrong.