Which of the following pure liquids is the best solvent for sodium fluoride?
CCl4
C2C6
HCl
BCl3
or PCl5
My guess would be either CCl4 or C2C6, I need to know the reasoning behind the correct answer.
Some of these choices I don't get. What's C2C6?
HCl a pure liquid? Hogwash.
PF5 a pure liquid? likewise.
Isn't BCl3 a gas?
To determine which of the given pure liquids is the best solvent for sodium fluoride, we need to consider the solubility characteristics of sodium fluoride and the properties of the solvents. Sodium fluoride (NaF) is an ionic compound with the formula NaF.
When an ionic compound dissolves in a solvent, the solvent molecules surround the ions to solvate or stabilize them, allowing them to disperse evenly throughout the solution. The solvent must have the ability to interact with the ions in a way that can overcome the attractive forces holding the ions together.
The solubility of sodium fluoride depends on the nature of the solvent molecules. Ideally, the solvent should have similar polar characteristics as sodium fluoride to facilitate solvation. Let's analyze the options one by one:
1. CCl4 (carbon tetrachloride): CCl4 is a nonpolar solvent. Since sodium fluoride is an ionic compound, it requires a polar solvent for effective solvation. As CCl4 is nonpolar, it may not interact strongly with the sodium and fluoride ions. Therefore, CCl4 is not a suitable solvent for sodium fluoride.
2. C2C6 (hexane): Hexane is a nonpolar solvent, similar to CCl4. As mentioned before, nonpolar solvents do not possess the necessary polarity to solvate ionic compounds effectively. Hence, hexane is also not a good choice for sodium fluoride.
3. HCl (hydrochloric acid): HCl is a strongly polar covalent compound. While it can dissolve some ionic compounds, HCl may not be the best choice for sodium fluoride because it can potentially react with NaF, forming different compounds. Therefore, HCl is not the optimal solvent for sodium fluoride.
4. BCl3 (boron trichloride): BCl3 is a polar molecule and can form coordinate bonds with the fluoride ion through its vacant p-orbital. This ability to form coordinate bonds may promote the solvation of sodium fluoride. However, BCl3 is not a commonly used solvent due to its reactivity and volatility. Hence, it may not be the best choice as a solvent for sodium fluoride from a practical standpoint.
5. PCl5 (phosphorus pentachloride): PCl5 is a polar covalent compound and can also form coordinate bonds with the fluoride ion. It has a higher polarity compared to BCl3. Phosphorus pentachloride is also more commonly used than BCl3 as a solvent. Therefore, PCl5 is the most suitable solvent for sodium fluoride among the options provided.
In conclusion, the best solvent for sodium fluoride among the given options is PCl5. It possesses the required polarity and can effectively solvate sodium fluoride.