In a chemical equation, which symbol should be used to indicate that a substance is in solution?

Formic acid can react with NaOH in aqueous solution to produce the formate ion, HCOO⁻. Write the balanced chemical equation for this reaction.

Write an equation for the precipitation reaction that occurs (if any) when you mix solutions of ammonium chloride and iron(III) nitrate mix.

Enter the molecular equation representing aqueous acetic acid neutralized by aqueous barium hydroxide.

Identify the precipitate (if any) that forms when KOH and Cu(NO₃)₂ are mixed.