Which salt is soluble in water according to Solubility Rule #1?

Which salt is soluble in water according to Solubility Rule #1?

• A. Silver Chloride
• B. Calcium Sulfate
• C. Barium Carbonate
• D. Sodium Acetate

Answer: (D)

Solubility Rule #1 says that salts of alkali metals (group 1A) are soluble in water. Sodium acetate fits this rule because it contains the alkali metal sodium (Na+) paired with the acetate anion (CH3COO−). In water, the Na+ and CH3COO− ions are strongly hydrated and the lattice energy of the solid is overcome, so the salt dissolves readily. The acetate ion is a common anion that stays dissolved, so you get a true aqueous solution. The other salts don’t have a group 1A cation: silver chloride is famously insoluble, calcium sulfate is only sparingly soluble, and barium carbonate is largely insoluble under ordinary conditions. Hence, sodium acetate is the soluble one according to this rule.

Solubility Rule #1 says that salts of alkali metals (group 1A) are soluble in water. Sodium acetate fits this rule because it contains the alkali metal sodium (Na+) paired with the acetate anion (CH3COO−). In water, the Na+ and CH3COO− ions are strongly hydrated and the lattice energy of the solid is overcome, so the salt dissolves readily. The acetate ion is a common anion that stays dissolved, so you get a true aqueous solution.

The other salts don’t have a group 1A cation: silver chloride is famously insoluble, calcium sulfate is only sparingly soluble, and barium carbonate is largely insoluble under ordinary conditions. Hence, sodium acetate is the soluble one according to this rule.