chemistry
posted by Fai .
How to calculate PH 1.9 =0.0126M
I do not still understand. I want you step by step to calculate for me.
Thank you.

I do these this way.
pH = log(H^+)
1.9 = log(H^+)
1.9 = log(H^+).
Now enter 1.9 on your calculator and hit the 10^{x} key. The answer of 0.01259 will appear.
This is just math. You may have seen it this way.
(H^+)= 10^{1.9}
Enter 10, then y^{x} key, then 1.9, press = and the answer of 0.01259 will appear. 
the answer is rounded off to 4 significant digits.