Question

the reaction below demonstrates which characteristic of a base?
$ce{cuso_{4}(aq) + 2naoh(aq) -> cu(oh)_{2}(s) + na_{2}so_{4}(aq)}$

• the ability of bases to release sodium ions into solution
• the ability of bases to release hydrogen ions into solution
• the ability of a base to react with carbonate or bicarbonate
• the ability of a base to react with a soluble metal salt

Explanation:

1. Analyze the reaction: $\ce{CuSO_{4}(aq)}$ (a soluble metal salt, copper(II) sulfate) reacts with $\ce{NaOH(aq)}$ (a base, sodium hydroxide).
2. Evaluate the first option: Bases don't release sodium ions as a defining characteristic of bases (sodium is specific to $\ce{NaOH}$ here, not a general base property).
3. Evaluate the second option: Bases release hydroxide ions ($\ce{OH^-}$), acids release hydrogen ions ($\ce{H^+}$), so this is incorrect.
4. Evaluate the third option: The reaction is with a metal salt ($\ce{CuSO_{4}}$), not a carbonate/bicarbonate, so this is incorrect.
5. Evaluate the fourth option: The reaction shows $\ce{NaOH}$ (base) reacting with soluble $\ce{CuSO_{4}}$ (metal salt) to form a precipitate ($\ce{Cu(OH)_{2}}$) and another salt ($\ce{Na_{2}SO_{4}}$), which matches the description of a base reacting with a soluble metal salt.

Answer:

the ability of a base to react with a soluble metal salt