Which equation has both a liquid and a gas as products?

A. [tex]2 HgO (s) \rightarrow 2 Hg (l) + O_2 (g)[/tex]

B. [tex]2 Mg (s) + O_2 (g) \rightarrow 2 MgO (s)[/tex]

C. [tex]2 KClO_3 (s) \rightarrow 2 KCl (s) + 3 O_2 (g)[/tex]

D. [tex]Mg (s) + 2 HCl (aq) \rightarrow H_2 (g) + MgCl_2 (aq)[/tex]



Answer :

To determine which of the given equations has both a liquid and a gas as products, we need to analyze the products of each equation carefully.

### Equation 1:
[tex]\[ 2 \text{HgO (s)} \rightarrow 2 \text{Hg (l)} + \text{O}_2 \text{(g)} \][/tex]
- Products:
- Mercury (Hg) which is in a liquid state (l)
- Oxygen (O₂) which is in a gaseous state (g)

This equation produces both a liquid (Hg) and a gas (O₂).

### Equation 2:
[tex]\[ 2 \text{Mg (s)} + \text{O}_2 \text{(g)} \rightarrow 2 \text{MgO (s)} \][/tex]
- Products:
- Magnesium oxide (MgO) which is in a solid state (s)

This equation does not produce any liquids, only a solid (MgO).

### Equation 3:
[tex]\[ 2 \text{KClO}_3 \text{(s)} \rightarrow 2 \text{KCl (s)} + 3 \text{O}_2 \text{(g)} \][/tex]
- Products:
- Potassium chloride (KCl) which is in a solid state (s)
- Oxygen (O₂) which is in a gaseous state (g)

This equation produces a solid (KCl) and a gas (O₂), but no liquid.

### Equation 4:
[tex]\[ \text{Mg (s)} + 2 \text{HCl (aq)} \rightarrow \text{H}_2 \text{(g)} + \text{MgCl}_2 \text{(aq)} \][/tex]
- Products:
- Hydrogen (H₂) which is in a gaseous state (g)
- Magnesium chloride (MgCl₂) which is in an aqueous state (aq)

This equation produces a gas (H₂) and an aqueous substance (MgCl₂), but no liquid.

### Conclusion:
From the analysis, Equation 1:
[tex]\[ 2 \text{HgO (s)} \rightarrow 2 \text{Hg (l)} + \text{O}_2 \text{(g)} \][/tex]
is the only one that produces both a liquid (Hg) and a gas (O₂).

Therefore, the equation with both a liquid and a gas as products is Equation 1.