X is a salt of a halogen such as chlorine, bromine, iodine, or astatine (proton number 85). The reaction scheme below shows a sequence of reactions, with a solution of X used as the initial reagent. $X \xrightarrow[\text{AgNO}_3\text{(aq)}]{\text{HNO}_3\text{(aq)}}$ a precipitate $\xrightarrow{\text{an excess of dilute NH}_3\text{(aq)}}$ a colourless solution $\xrightarrow{\text{an excess of HNO}_3\text{(aq)}}$ a precipitate What might X be?
- Asodium chloride
- Bsodium bromide
- Cpotassium iodide
- Dpotassium astatide