Answer: Question #1) The formation of a precipitate
Question # 2) ? Insufficient information
Question # 3) when you mix baking soda (sodium bicarbonate) with vinegar (acetic acid) the baking soda is the base and the vinegar is the acid, the baking soda takes a proton from the acid and the products of the reaction are H2O and CO2. The initial two products are carbonic acid and sodium acetate and the second part of the reaction is the decomposition reaction with the carbonic acid immediately decomposing into water and carbon dioxide gas. The CO2 rises to the surface creating bubbles.
Question #4) when sodium hydroxide, a strong base reacts with copper sulfate an acidic salt as a blue precipitate of copper hydroxide is produced with ions of sodium sulfate in solution. This represents a double displacement reaction as well as a precipitation reaction.
Explanation: