To determine which equation has both a liquid and a gas as products, let's examine each given chemical reaction step-by-step.
1. First Equation:
[tex]\[
2 \, \text{HgO (s)} \rightarrow 2 \, \text{Hg (l)} + \text{O}_2 \, \text{(g)}
\][/tex]
- Here, we have mercury oxide (HgO) in solid form (s) decomposing into mercury (Hg) in liquid form (l) and oxygen (Oâ‚‚) in gas form (g).
2. Second Equation:
[tex]\[
2 \, \text{Mg (s)} + \text{O}_2 \, \text{(g)} \rightarrow 2 \, \text{MgO (s)}
\][/tex]
- This reaction involves magnesium (Mg) in solid form (s) reacting with oxygen (Oâ‚‚) in gas form (g) to produce magnesium oxide (MgO) in solid form (s).
- The products are solid only.
3. Third Equation:
[tex]\[
2 \, \text{KClO}_3 \, \text{(s)} \rightarrow 2 \, \text{KCl (s)} + 3 \, \text{O}_2 \, \text{(g)}
\][/tex]
- Potassium chlorate (KClO₃) in solid form (s) decomposes into potassium chloride (KCl) in solid form (s) and oxygen (O₂) in gas form (g).
- The products are a solid and a gas, but no liquid.
4. Fourth Equation:
[tex]\[
\text{Mg (s)} + 2 \, \text{HCl (aq)} \rightarrow \text{H}_2 \, \text{(g)} + \text{MgCl}_2 \, \text{(aq)}
\][/tex]
- Magnesium (Mg) in solid form (s) reacts with hydrochloric acid (HCl) in aqueous form (aq) to produce hydrogen (Hâ‚‚) in gas form (g) and magnesium chloride (MgClâ‚‚) in aqueous form (aq).
- The products are a gas and an aqueous solution, but no liquid.
By analyzing each equation, we see that the only equation where both a liquid and a gas are produced as products is the first one:
[tex]\[
2 \, \text{HgO (s)} \rightarrow 2 \, \text{Hg (l)} + \text{O}_2 \, \text{(g)}
\][/tex]
Thus, the correct equation is the first one.
Therefore, the answer is:
1.
