posted by Nia on .
Assuming equal concentrations , rank these solutions by pH. RbOH(aq), NH3(aq), HF(aq) HBr(aq), Ca(OH)2(aq).
I know the most acidic solution has the lowest pH and the most basic solution has the highest pH. But how am i supposed to know the pH if i don't know the concentration of each solution?
I think the secret is in the wording of the problem. It says assuming EQUAL concns.....
I would divide these into bases and acid.
RbOH, NH3 and Ca(OH)2.
RbOH is the highest OH, followed by Ca(OH)2 and NH3. I rank RbOH higher than Ca(OH)2 because Ca(OH)2 isn't a soluble as RbOH.
HBr is a strong acid; HF is a weak acid. You should be able to rank all of them now.
It was on my homework too and this came out right
In acids, more electronegativity is more acid power.
In bases, less electronegativity is more bas power.
Because H is positive and elements with high electronegativity pushs more H+. So with this our acid will be more powerful.
And as same as acids, we calculate bases powers with this way.
Less electronegative elements pushes more OH-. So our bas becomes more powerful.