In general chemistry, semester 2, students learn about acids and bases. Salts are ionic compounds that are produced from the reaction of an acid with a base. Salts can be acidic, basic or neutral.
How do we determine this?
First, we must memorize all the strong acids which are:HCl - hydrochloric acid, HBr - hydrobromic acid, HI - hydroiodic acid, HNO3 - nitric acid, HClO3 - chloric acid, HClO4 - perchloric acid, H2SO4 - sulfuric acid.
We have to also remember strong bases, which are group one and two with an OH (such as KOH, NaOH etc).
Thus we can make 2 charts:
Anions : Cl-, Br-, I-, NO3-, ClO3-, ClO4-, SO4 2-
Cations: Group 1 & 2 (Ex: K+, Li+ ......)
When looking at salt, if we cross out the cation from the list above, the salt is basic. If we cross out anion, then the salt is acidic. If we cross out both, the salt is neutral.
Why? A salt that was made from the reaction of strong acid with weak base is acidic. A salt that was made from the reaction of strong base with weak acid is basic. A salt made from the reaction of strong acid with strong base is neutral.
Let's take KF for example, we can cross ok K+ since its in the first group. Since we crossed out the cation only, this salt is basic. It came from a strong base, KOH, and a weak acid, HF.
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