Salts in Solution

Learn about salts in solution, equivalence points other than 7 and buffers in this video!

transcript
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Salts contain an anion from an acid and a cation from a base
Acids and bases mix to produce salts, but not always a neutral solution. Some salts actually cause water to break up into further ions. In general, salts that produce acidic solutions contain positive ions that release protons to water. Salts that produce basic solutions contain negative ions that attract protons from water.
in salt hydrolysis, the cations or anions of a dissociated salt remove hydrogen ions from or donate hydrogen ions to water. Not all salts will do this, only some will.
whenever we have a strong acid with a strong base, we get a neutral solution with salts that don’t do salt hydrolysis. when we mix a strong acid and a weak base, we end up with an acidic solution. a weak acid and a strong base will produce a basic solution.
Here is a graph of a titration of a strong acid and a strong base, sodium hydroxide. you can dee that the equivalence point is right in the middle of the vertical section of the graph, at a pH of 7. But if we look at a graph of a titration of a weak acid and a strong base, the equivalence point is slightly more basic, at almost a pH of 9. The salt produced cases more hydroxide ions to be produced, resulting in a more basic equivalence point.
A buffer is a solution of a weak acid and one of its salts, or a solution of a weak base and one of its salts. The pH of a buffer remains relatively constant when small amounts of acid or base are added. The buffer capacity is the amount of acid or base that can be added to a buffer solution before a significant change in pH occurs.
This graph shows that happens where more HCl is added to pure water over time. The pH is steadily decreasing. But when we have a buffer solution and we add HCl, the pH remains steady for a long time, then begins to change eventually, but nowhere near as drastically. Buffers keep the pH steady, and this is very important for many living systems, like the pH of your blood.

Видео Salts in Solution канала Teacher's Pet