Question

which of the following is not a multivalent ion?
ag⁺
sb⁵⁺
cu⁺
cr³⁺

Explanation:

A multivalent ion is an ion that can have more than one possible charge. Let's analyze each option:

• \( \text{Ag}^+ \): Silver (Ag) typically has a charge of \( +1 \) and does not commonly exhibit other stable charges (though in some rare cases, but generally considered to have a fixed charge of \( +1 \) in most common contexts).
• \( \text{Sb}^{5+} \): Antimony (Sb) can have multiple charges, such as \( +3 \) and \( +5 \), so it is multivalent.
• \( \text{Cu}^+ \): Copper (Cu) can have charges of \( +1 \) (cuprous) and \( +2 \) (cupric), so it is multivalent.
• \( \text{Cr}^{3+} \): Chromium (Cr) can have charges like \( +2 \), \( +3 \), and \( +6 \), so it is multivalent.

Since \( \text{Ag}^+ \) does not have multiple common stable charges (unlike the others), it is not a multivalent ion.

Answer:

\( \text{Ag}^+ \) (the option with \( \text{Ag}^+ \))