Solubility and Dissociation

KBr

• Soluble

• Insoluble

Answer explanation

KBr, or potassium bromide, is soluble in water due to its ionic nature. The strong interactions between the ions and water molecules allow it to dissolve easily, making 'soluble' the correct choice.

Zinc Hydroxide

• Soluble 

• Insoluble

Answer explanation

Zinc hydroxide is classified as insoluble in water. It does not dissolve significantly, which is why the correct answer is 'Insoluble'.

Silver Iodide

• Soluble 

• Insoluble 

Answer explanation

Silver iodide is known to be insoluble in water. This property is due to the strong ionic bonds between silver and iodide ions, which do not easily dissociate in aqueous solutions, confirming that the correct answer is 'Insoluble'.

Zinc Carbonate

• Soluble 

• Insoluble 

Answer explanation

Zinc carbonate is generally considered insoluble in water. This property is due to its ionic structure, which does not easily dissociate in aqueous solutions, confirming that the correct answer is 'Insoluble'.

Silver acetate

• Soluble 

• Insoluble

Answer explanation

Silver acetate is soluble in water due to its ionic nature, allowing it to dissociate into silver and acetate ions. This solubility is characteristic of many acetate salts.

KOH

• Soluble 

• Insoluble

Answer explanation

KOH, or potassium hydroxide, is soluble in water. It dissociates into potassium ions and hydroxide ions, making it a strong base and highly soluble in aqueous solutions.

NiCl₂

• Soluble 

• Insoluble

Answer explanation

NiCl2 is soluble in water due to the ionic nature of the compound, which allows it to dissociate into Ni²⁺ and Cl⁻ ions, making it soluble in polar solvents like water.

PbI₂

• Soluble

• Insoluble

Answer explanation

PbI2 is considered insoluble in water due to the low solubility of lead(II) iodide in aqueous solutions, which is a characteristic of many lead salts.

A bottled water label lists the ions dissolved in the water.  The table below lists the mass of some ions dissolved in a 500.-gram sample of the bottled water.

Based on Table F, write the formula of the ion in the bottled water table that would form the least soluble compound when combined with the sulfate ion.

• Ca⁺²

• Mg⁺²

• Na⁺

• HCO₃^-

Answer explanation

Ca⁺² forms the least soluble compound with sulfate (CaSO₄), compared to Mg⁺², Na⁺, and HCO₃^-, which form more soluble compounds.

Explain the solubility of ionic compounds.

• Ionic compounds are soluble in water due to the attraction between the ions and water molecules.

• Ionic compounds are soluble in air due to the attraction between the ions and air molecules.

• Ionic compounds are insoluble in water due to the repulsion between the ions and water molecules.

• Ionic compounds are soluble in oil due to the attraction between the ions and oil molecules.

Answer explanation

Ionic compounds dissolve in water because the positive and negative ions are attracted to the polar water molecules, allowing them to separate and disperse in solution. This attraction is not present with air or oil.