Write a balanced equation for
(a) the combination reaction between lithium metal and fluorine gas and
(b) the decomposition reaction that occurs when solid barium carbonate is heated (two products form, a solid and a gas).
The correct answer and explanation is:
Certainly! Here’s the answer to both parts:
(a) Combination reaction between lithium metal and fluorine gas
Reaction: Lithium (Li) reacts with fluorine gas (F₂) to form lithium fluoride (LiF).
Balanced equation: 2Li(s)+F2(g)→2LiF(s)\boxed{ 2 \mathrm{Li} (s) + \mathrm{F}_2 (g) \rightarrow 2 \mathrm{LiF} (s) }
(b) Decomposition reaction of solid barium carbonate on heating
When barium carbonate (BaCO₃) is heated, it decomposes into barium oxide (BaO), a solid, and carbon dioxide (CO₂), a gas.
Balanced equation: BaCO3(s)→ΔBaO(s)+CO2(g)\boxed{ \mathrm{BaCO}_3 (s) \xrightarrow{\Delta} \mathrm{BaO} (s) + \mathrm{CO}_2 (g) }
Explanation (approx. 300 words):
(a) Combination reaction between lithium and fluorine:
A combination reaction, also called a synthesis reaction, involves two or more reactants combining to form a single product. Here, lithium metal, a highly reactive alkali metal, reacts with fluorine gas, a diatomic halogen. Fluorine is extremely electronegative and reacts vigorously with lithium.
Lithium atoms each lose one electron to form Li⁺ ions, while fluorine molecules split into two fluorine atoms, each gaining one electron to form two F⁻ ions. These ions combine to form ionic lithium fluoride (LiF), a stable solid compound.
The balanced equation reflects that one molecule of F₂ reacts with two atoms of lithium to form two formula units of lithium fluoride. This preserves the atom count: 2 lithium atoms and 2 fluorine atoms on both sides.
(b) Decomposition of barium carbonate:
Decomposition reactions occur when a compound breaks down into two or more simpler substances, often upon heating. Barium carbonate (BaCO₃) is a common inorganic salt used in various industrial processes.
Upon heating, BaCO₃ decomposes into barium oxide (BaO), which remains solid, and carbon dioxide gas (CO₂), which escapes. This is a typical thermal decomposition reaction of metal carbonates.
The reaction is: BaCO3(s)→ΔBaO(s)+CO2(g)\mathrm{BaCO}_3 (s) \xrightarrow{\Delta} \mathrm{BaO} (s) + \mathrm{CO}_2 (g)
No additional balancing is necessary because the equation already conserves atoms: one barium atom, one carbon atom, and three oxygen atoms on each side.
This reaction is important in processes like the production of barium oxide, which is used in ceramics and glass manufacturing. It also demonstrates the release of carbon dioxide gas, a greenhouse gas relevant in environmental chemistry.