If 35.00 mL of 0.25 M NaOH(aq) is mixed w/ 20.00 mL of 0.400 M HClO4(aq), the result solution would be:

Question

So apparently the correct answer is BASIC, but I thought it would be neutral because the resulting solution would contain NaClO4 which has components of both a strong acid and a strong base. How could this be?

Answer 1

Moles base: .035*.25=.00875
moles acid: .020*.4=.00800
So you have excess base, and the resultant is basic solution

Answer 2

You are right IF you had some solid NaClO4 and placed it in a beaker of water. BUT you didn't have that. How many mols NaOH did you have? How many mols HClO4 did you have?
mols NaOH = M x L = 0.25 x 0.03500 = 0.00875
mols HClO4 = M x L = 0.400 x 0.0200 = 0.008

So you have enough NaOH to neutralize ALL of the HClO4 and have some NaOH left over which makes it basic.

Answer 3

So that means it would be neutral only if there was an equal amount of both NaOH and HClO4, correct?

Answer 4

That is correct.