Question

hydrocyanic acid express your answer as a chemical formula.

Explanation:

Step1: Identify the ions

Hydrocyanic acid is an acid, so it contains the hydrogen ion ($\ce{H+}$) and the cyanide ion ($\ce{CN-}$).

Step2: Combine ions to form formula

To form a neutral compound, the positive charge of the hydrogen ion and the negative charge of the cyanide ion balance each other. So the chemical formula is formed by combining $\ce{H+}$ and $\ce{CN-}$, resulting in $\ce{HCN}$.

Answer:

$\ce{HCN}$