Which pH result is correct? What am I doing wrong? Please explain.

Hello, I've been struggling with this exercise because I don't know which pH result is correct.

 

I was given:

Calculate pH

pKa = 10.25

[HCO^-₃] = 25.2 mmol/L --> 2.52 x10^-3

[CO₃^-2] = 32.0 umol/L --> 3.2 x10^-5

 

So, pH = pKa + log ([A^-]/[HA])

 

The correct answer should be (the answer in the book): pH = 7.4

 

But I keep getting: pH = 13.1, what am I doing wrong?