Which one of the following salts gives an acidic solution in water?

$A$ graph of magnetic flux $(\phi)$ versus current $(I)$ is drawn for four inductors $A, B, C, D$. Which inductor has the largest value of self-inductance?

Statement-$I$: Two lines which pass through a given fixed point and are equally inclined to two other lines passing through the same point,are always perpendicular to each other.
Statement-$II$: Angle bisectors of two intersecting lines are always perpendicular to each other.

$23 \ g$ of $Na$ metal reacts with ethanol to produce which of the following?

Let $A = \{1, 2, \{3, 4\}, 5\}$. Which of the following statements is incorrect and why?
${3, 4} \subset A$

Which one of the following compounds does not decolourise an acidified aqueous solution of $KMnO_4$?