1. Salts of a weak acid and a strong base produce solutions that are basic.
Thatâs because  the salt of a weak acid hydrolyzes in water to form hydroxide ions.
A- + HâO â HA + OHâ» Â
2. The common ion effect is the phenomenon in which the addition of a charged particle common to two solutes decreases the solute concentration.
AgCl(s) â Agâș(aq) + Clâ»(aq)
The addition of NaCl reduces the concentration of Agâș because the added common ion (Clâ») forces the position of equilibrium to shift to the left.
3. When hydrogen peroxide decomposes naturally, the products are oxygen and water.
2HâOâ â¶Oâ + 2HâO
4. An oxidizing agent is the substance that is reduced.
[tex]2\stackrel{\hbox{0}}{\hbox{Na }} +\stackrel{\hbox{0}}{\hbox{ Cl}}_{2} \longrightarrow 2\stackrel{\hbox{+1}}{\hbox{Na}}\stackrel{\hbox{-1}}{\hbox{Cl}}\\[/tex]
The Na is oxidized, so the Cl atoms in Clâ are the oxidizing agent.
The oxidation number of Cl goes from 0 to -1, so Cl is reduced.