so is that mean
100/1000 x 0.5 + 200/1000 x 0.1
= 0.05 + 0.02
= 0.07
So far so good. 0.07 mole of HCl.
then 0.07 x 300/1000 = 0.021
Divide by the volume, not multiply.
so is 0.07 x 1000/300 = 0.233
then pH = -log 0.2333 = 0.632 ?
or
0.07/300 = 0.000233
then pH = -log 0.000233 = 3.633 ?
which one is correct? thx so much for your help