[Sayanthan]

When 20 mL of 0.300 mol/L HCl(aq) is titrated with 10 mL of 0.300 mol/L NaOH(aq), what is the pH of the solution?
Please include steps to answer the question. Thanks in advance. 

[Borek]

Sorry, accidentally deleted your post with an attempt...

Because the two solutions have equal molarity, and HCl and NaOH react 1:1 , you will have 10ml of 0.300M HCl unreacted.

Mol HCl in 10ml 0.300M solution:
10/1000*0.300 = 0.003mol HCl
Total volume of solution = 20+10 = 30 ml.
What is the molarity of 0.003 mol HCl dissolved in 30ml solution:
1000/30*0.003 = 0.1M

Because [HCl] = 0.1M, [H+] = 0.1M

pH = -log [H+]
pH = -log 0.1
pH = 1.00

OK