please help me to understand

Question

The 

 scale for acidity is defined by 

 where 

is the concentration of hydrogen ions measured in moles per liter (M).

A solution has a 

 of 12.35.

Calculate the concentration of hydrogen ions in moles per liter (M). Write the answer in scientific notation.

The concentration of hydrogen ions is  ____moles per liter.

Thank you !!!

Answer 1

12.35 = -log (H+)

-12.35 = log(H+)

10^-12.35 = 10^log(H+)

10^-12.35 = H+

4.4668359215096311855625052431938e-13