Question

Which among the following is a soluble hydroxide?

• A. $N{H}_{4}OH$
• B. $Al(OH{)}_3$
• C. $Co(OH{)}_2$
• D. $Fe(OH{)}_3$

Answer 1

The correct option is A $N{H}_{4}OH$

Option $\left(A\right)$ is correct. $N{H}_{4}OH$ is a soluble hydroxide.

Salts containing the ammonium ion ($N{H}_4^{+}$) are also soluble.

Most hydroxide salts are only slightly soluble. Hydroxide salts of Group $I$ elements are soluble. Hydroxide salts of Group $II$ elements ($Ca,Sr,$ and $Ba$) are slightly soluble. Hydroxide salts of transition metals and $A{l}^{3+}$ are insoluble. Thus, $Fe(OH{)}_3,Al(OH{)}_3,Co(OH{)}_2$ are not soluble.