Achieve #10

[Madysen Ratsek 3L]

Hello, for the Achieve question:
Assuming equal concentrations, arrange these solutions by pH. (NH3, Sr(OH)2, HClO4, HF, and RbOH)

How would we go about determining the OH- and H+ concentrations of these compounds? Is this the first step in determining pH? Thanks in advance!

[505686385]

For this question, I started off with knowing that the highest pH (like a pH of 14) is the one with a stronger base and the lowest pH (like a pH of 1) is the one with a stronger acid. When determining which base is stronger, the less electronegative an atom is; the more basic it likely is. Electronegativity increases going across to the right of the periodic table and decreases going downwards. When determining which acid is stronger, the weaker acid has shorter and stronger bonds, whereas the stronger acid has longer and weaker bonds. Bond length increases as you move down the periodic table because the atom size also increases, creating more space between the bonding atoms.

[Joseph Liao 3C]

It would definitely help to begin by identifying which acids/bases are strong vs. weak. Here is a link that may help with that:
https://sites.google.com/site/chempendi ... cids-bases
Then, it would be helpful to know that bases that form with group 1 metals are stronger than ones that form with group 2 metals.

I hope that helps!