Answer
Options (a), (c), (d), and (e) conduct electricity.
Option (b) does not conduct electricity.
(a) Al$^{3+}$, Br$^-$
(c) Ca$^{2+}$, NO$_3$$^-$
(d) NH$_4$$^+$, SO$_4$$^{2-}$
(e) K$^+$, Cr$_2$O$_7$$^{2-}$
Work Step by Step
A substance conducts electricity if it dissociates into its constituent ions when dissolved in water. These substances are also known as ionic compounds.
Molecular compounds in which electrons are shared between atoms within the molecule do not dissociate in water. These types of compounds do not produce ions in water and, thus, do not conduct electricity.
Options (a), (c), (d), and (e) are ionic compounds and conduct electricity.
Option (b) is a molecular compound and does not conduct electricity.
(a) Al$^{3+}$, Br$^-$
(c) Ca$^{2+}$, NO$_3$$^-$
(d) NH$_4$$^+$, SO$_4$$^{2-}$
(e) K$^+$, Cr$_2$O$_7$$^{2-}$
