[Joules23]

im having trouble with this:
find the pH of:

a) 100mL x .365% HCl + 200mL x .20% NaOH

b) 100mL x .20M HOAc + 100mL x.10M Ba(OH)2

are there any guides out there that would walk me through the problem? because i dont know where to begin

[Borek]

100mL x .365% HCl + 200mL x .20% NaOH

http://www.chembuddy.com/?left=pH-calculation-questions&right=pH-of-mixture-q1

You sure these are % concentrations? If so, don't forget to convert them to molar.

100mL x .20M HOAc = 100mL x.10M Ba(OH)2

First of all - write balanced reaction equation and check stoichiometry.

[Joules23]

sorry about that, i mean to put + not a = for part (b)

Can someone check my work for part (a), this is what i did

first to convert to mols for HCl : .365g/36.46g = .01mols,
then to get Molarity: .01mols/.1Liter = .1M

i did the same thing for NaOH and got .05M

next i multiplied 100mL x .1M = 10mmol NaOH
200 x .025 = 10 mmol NaOH

10-10=0

PH= 7, right?

[Joules23]

EDIT: ok i got part a down, somehow i missed this part

"Note that if there is exactly the same amount of both reactants reaction proceeds to the end - and you are left with perfectly neutral solution of pH=7.00." -chembuddy.com

I still need help on part (b)
HOAC + Ba(OH)2 -> H(OH)2 + BaAcO

is that right?

[Borek]

HOAC + Ba(OH)2 -> H(OH)2 + BaAcO

No, it is not balanced. HOAc (or AcOH, or AcH - everyone uses his own notation here) is most likely acetic acid, and it dissociates:

AcOH <-> AcO^- + H⁺

Now try to write balanced reaction equation.

[Joules23]

can you show me an example of a reaction equation?

[Borek]

NaOH + AcOH -> AcONa + H₂O

Simple neutralization, in every other aspect identical to

NaOH + HCl -> NaCl + H₂O