Solid mercury(II) oxide decomposes to produce liquid mercury metal and gaseous oxygen. (Write the formulas for the substances and phases in the order given above.)
- Phase Write Symbol As
- solid (s)
- liquid (l)
- gas
- aqueous (aq)
The correct answer and explanation is :
The decomposition of solid mercury(II) oxide can be written in terms of its chemical equation as follows:
2HgO(s) → 2Hg(l) + O₂(g)
Here’s a breakdown of the phases and the corresponding symbols:
- HgO (mercury(II) oxide) is a solid, so the phase symbol is (s).
- Hg (mercury) is a liquid at room temperature, so the phase symbol is (l).
- O₂ (oxygen) is a gas at room temperature, so the phase symbol is (g).
Explanation:
Mercury(II) oxide (HgO) is an inorganic compound that undergoes a decomposition reaction when heated. The heat causes the bonds in mercury(II) oxide to break, leading to the formation of mercury metal (Hg) and oxygen gas (O₂).
- Mercury(II) oxide (HgO): Mercury(II) oxide is a red or yellowish solid compound at room temperature. In the reaction, this solid decomposes when heated, breaking into its constituent elements: mercury and oxygen. The phase symbol for a solid is represented by (s).
- Mercury (Hg): Mercury, in its elemental form, is a heavy liquid at room temperature. This is one of the unique aspects of mercury; unlike most metals that are solids at room temperature, mercury is a liquid. The phase symbol for a liquid is (l).
- Oxygen (O₂): Oxygen gas is a diatomic molecule (O₂) and, at room temperature, it is in the gaseous state. The phase symbol for a gas is (g).
This decomposition reaction is commonly used in laboratory demonstrations to show the process of thermal decomposition. The reaction is also important in historical contexts, as it was one of the first examples of a decomposition reaction studied in chemistry. The reaction also highlights how the phases of matter are important in distinguishing between different substances involved in a chemical reaction.
In summary, the complete reaction with the correct phase symbols is:
2HgO(s) → 2Hg(l) + O₂(g)