Sure, let’s discuss the given chemical reaction and determine the correct formula equation step-by-step.
1. Identify the Reactants and Products:
- Fluorine gas is placed in contact with calcium metal at high temperatures to produce calcium fluoride.
2. Analyze Each Option:
- Option 1:
[tex]\[ F_2 (l) + Na (s) \longrightarrow NaF_2 (s)\][/tex]
- Incorrect because fluorine is in a liquid state and sodium (Na) is incorrect as we need calcium (Ca) to produce calcium fluoride.
- Option 2:
[tex]\[ F_2 (g) + Ca (s) \xrightarrow{\longrightarrow} CaF_2 (l)\][/tex]
- Correct reactants: Fluorine gas (\( F_2 \)) and calcium solid (\( Ca \)).
- Correct product: Calcium fluoride (\( CaF_2 \)).
- Correct states: \( F_2 \) is a gas and \( Ca \) is a solid at high temperatures, and \( CaF_2 \) can be in a liquid state at very high temperatures.
- Option 3:
[tex]\[ F_2 (g) + Na (s) \xrightarrow{\Delta} NaF_2 (l)\][/tex]
- Incorrect because sodium (Na) is not the correct metal we need; we need calcium (Ca).
- Option 4:
[tex]\[ F_2 (g) + Ca (s) \xrightarrow{\operatorname{Ca}} F_2 (s)\][/tex]
- Incorrect as the product should be \(CaF_2\) (calcium fluoride), not fluorine solid (\( F_2 \)).
Based on the analysis, the correct formula equation that matches the reaction described, “Fluorine gas is placed in contact with calcium metal at high temperatures to produce calcium fluoride powder”, is:
[tex]\[ F_2 (g) + Ca (s) \xrightarrow{\longrightarrow} CaF_2 (l) \][/tex]
Therefore, the correct answer is [tex]\( 2 \)[/tex].
