Acid-Base and Double Replacement Reactions

This unit focuses on chemical reactions, and the chemical reactions that we have learned so far are acid-base and double replacement. Acid-base, obviously deals with reactions with acids and bases that form water and a salt as a product. Double replacement reactions deal with aqueous ionic compounds that form solids as products.

Acid-Base Reactions:

• An acid and a base are placed together, and they react to neutralize the acid and base properties, producing a salt
• A typical acid-base reaction consisting of both a strong acid and a strong base looks like this:

HCl (a strong acid) combines with NaOH (a strong base) to form water and NaCl. In this reaction, the reactant cations switch to form the products.

• When the acids are weak, they do not disassociate in the reaction when showing the complete ionic formula of the reaction, but they do give off enough H or OH to react and form water as a product.
• Weak acid+strong base will always have the structure of:

 HA+OH-->H2O+A

Strong Acid Rules and Examples:

• HCl (hydrochloric acid)
• HBr (hydrobromic acid)
• HI (hydroiodic acid)
• Any acid where oxygens outnumber hydrogens by two or more (ex. HClO4)

Strong Base Rules:

• Cations from group 1 or 2
• All bases have an -OH anion

Common Weak Acids:

• HF (hydrofluoric acid)
• HC2H3O2 (acetic acid)

Crash Course Acid-Base Reaction Video

Double Replacement Reactions:

• Follows this format:

• The driving force is the production of a solid, so if no solid is formed, it is not a completed reaction.
• Can determine if products are solid using solubility rules

Ba and Mg are the cations, and they switch places to create the products.

Crash Course Double Replacement Reaction Video

Helpful Links:

Acid-Base Reaction Notes

Double Replacement Reaction Notes