Lower pH w/ Equal Vol 0.60M NaOH: 0.70 M KOH

[ThatDude]

Homework Statement

To which of the following would the addition of an
equal volume of 0.60 M NaOH lead to a solution
having a lower pH? (a) water, (b) 0.30 M HCl,
(c) 0.70 M KOH, (d) 0.40 M NaNO3.

2.The attempt at a solution
the correct answer is 0.70 M KOH, and they say that by adding more OH you are producing a left shift. Okay, that's cool.

My answer is 0.30 M HCl, this is because adding a strong acid will increase H+ concentration, OH- concentration will go down, therefore pH will decrease. Why is this wrong?

 

[epenguin]

Homework Statement

To which of the following would the addition of an
equal volume of 0.60 M NaOH lead to a solution
having a lower pH? (a) water, (b) 0.30 M HCl,
(c) 0.70 M KOH, (d) 0.40 M NaNO3.

2.The attempt at a solution
the correct answer is 0.70 M KOH, and they say that by adding more OH you are producing a left shift. Okay, that's cool.

My answer is 0.30 M HCl, this is because adding a strong acid will increase H+ concentration, OH- concentration will go down, therefore pH will decrease. Why is this wrong?

You might have misread the question: acid is not being added.

 

[Borek]

Perhaps I am missing something, but I don't get the question - in each case after adding NaOH pH goes up, it never goes down, thus it can't be lower.

 

[epenguin]

I think you are slightly missing it.

 

[Borek]

Geez, got it. What a brain fart