Question

Rank these in order from most acidic to most basic.

Answer 1

How do I figure out their acidity or alkalinity?

Answer 2

\(\Large pH=-log[H^+]\)

The lower the pH, the higher the acidity

Answer 3

First find out the pH of all 4. then you can order them

Answer 4

For 0.0018M KOH you need to figure out the pOH and then convert that to pH (see the conversion diagram I posted).
for pOH=8.55 you convert that to pH
0.0023M HCl, just use pH=-log[H+] H+ is just 0.0023M since there is only 1 H in the compound. Same for KOH, the OH- concentration is 0.0018M because there is only 1 OH.
Last one, the pH is already given.

Then order them from low pH (acidic) to high pH (basic)