Question

Which of the following will form alums?

• A. $L{i}^{+}$
• B. $N{a}^{+}$
• C. $A{l}^{3+}$
• D. $C{r}^{3+}$

Answer 1

Answer: (B), (C), (D)

$N{a}^{+}$
$A{l}^{3+}$
$C{r}^{3+}$

Alum, any of a group of hydrated double salts, usually consisting of aluminium sulfate, the water of hydration, and the sulfate of another element. Thus to form alums with sulfates of the singly charged cations of potassium, sodium, chromium, ammonium, cesium, and other elements and compounds.

So options B, C, D are correct