Answer: The number of ions of [tex]K^+[/tex] are [tex]30.11\times 10^{23}[/tex] and number of ions of [tex]S^{2-}[/tex] are [tex]15.055\times 10^{23}[/tex].
Explanation:
Potassium sulfide, [tex]K_2S[/tex] is an ionic compound. The dissociation of this compound in water will yield:
[tex]K_2S\rightarrow 2K^++S^{2-}[/tex]
By Stoichiometry,
One mole of potassium sulfide dissociates into 2 moles of potassium ions and 1 mole of sulfide ion.
According to mole concept:
1 mole of an ionic compound contains [tex]6.022\times 10^{23}[/tex] number of ions.
So, 2.5 moles of [tex]K_2S[/tex] will contain [tex]2.5\times 2\times 6.022\times 10^{23}=30.11\times 10^{23}[/tex] number of [tex]K^{+}[/tex] ions and [tex]2.5\times 1\times 6.022\times 10^{23}=15.055\times 10^{23}[/tex] number of [tex]S^{2-}[/tex] ions.
Hence, the number of ions of [tex]K^+[/tex] are [tex]30.11\times 10^{23}[/tex] and number of ions of [tex]S^{2-}[/tex] are [tex]15.055\times 10^{23}[/tex].