Here's the balanced chemical equation:
Sr(NO₃)₂ (aq) + Na₂S (aq) → SrS (s) + 2NaNO₃ (aq)
Explanation:
* Double Displacement: The positive and negative ions of the reactants switch partners.
* States of Matter:
* Strontium nitrate (Sr(NO₃)₂) and sodium sulfide (Na₂S) are both soluble in water, so they are written as (aq) for aqueous solutions.
* Strontium sulfide (SrS) is insoluble in water, so it precipitates out of solution as a solid (s).
* Sodium nitrate (NaNO₃) remains dissolved in the solution (aq).
* Solubility: The solubility rules help predict whether a product will be soluble or insoluble. In this case, sulfides (except for those with Group 1 cations and ammonium) are generally insoluble.
* Balancing: The equation is balanced to ensure an equal number of atoms of each element on both sides of the reaction.
Key Observations:
* A white precipitate of strontium sulfide (SrS) will form.
* The solution will remain clear, but the presence of sodium nitrate (NaNO₃) can be confirmed by additional tests.
Note: This reaction is also considered a precipitation reaction because it involves the formation of a solid precipitate.
