Water is a polar solvent and pentane (C5H12) is a non polar solvent. Which of the following correctly describes the solubility of the solute?
A) oil, soluble in water
B) KBr, soluble in pentane
C) 12, soluble in water
D) C2H6, soluble in water
E) Lici, soluble in water
The Correct Answer and Explanation is :
The correct answer is E) LiCl, soluble in water.
Explanation:
To understand the solubility of solutes in different solvents, it’s crucial to know the principle of “like dissolves like.” This principle means that polar solvents tend to dissolve polar solutes, and non-polar solvents tend to dissolve non-polar solutes.
- A) Oil, soluble in water: Oil is typically a non-polar substance, while water is a polar solvent. Since polar solvents do not mix well with non-polar substances, oil is insoluble in water. Therefore, this statement is incorrect.
- B) KBr, soluble in pentane: KBr (potassium bromide) is an ionic compound, and ionic compounds generally dissolve in polar solvents like water, due to the interaction between the ions and the solvent’s dipole. Pentane, on the other hand, is non-polar, and ionic compounds do not dissolve well in non-polar solvents. Hence, this statement is incorrect.
- C) C12, soluble in water: C12 refers to a molecule of 12 carbon atoms (likely a hydrocarbon chain). Hydrocarbons are non-polar molecules and are generally insoluble in polar solvents like water. Therefore, this statement is incorrect.
- D) C2H6, soluble in water: C2H6, or ethane, is a non-polar hydrocarbon, and as mentioned earlier, non-polar solutes do not dissolve well in polar solvents like water. Thus, this statement is incorrect.
- E) LiCl, soluble in water: LiCl (lithium chloride) is an ionic compound. Ionic compounds typically dissolve in polar solvents, as the positive and negative ions are stabilized by the polar nature of the solvent. Water, being a polar solvent, can break the ionic bonds in LiCl and dissolve it. Therefore, this statement is correct.
Thus, the only correct statement is E) LiCl, soluble in water.