Question

a polyatomic ion usually refers to a covalently bonded group of two or more elements that, together, have a charge. the charge on a polyatomic ion is usually negative, but there are positively charged polyatomic ions, as well. which of the following compounds contains a polyatomic ion? baco₃ kcl h₂so₄ mgcl₂

Explanation:

• For \(BaCO_3\), it dissociates into \(Ba^{2 +}\) and \(CO_3^{2-}\). The \(CO_3^{2-}\) (carbonate ion) is a polyatomic ion as it is a covalently - bonded group of \(C\) and \(O\) atoms with a charge.
• For \(KCl\), it dissociates into \(K^{+}\) and \(Cl^{-}\). Both \(K^{+}\) and \(Cl^{-}\) are monatomic ions.
• For \(H_2SO_4\), in the context of ionic dissociation (in aqueous solution), it dissociates into \(2H^{+}\) and \(SO_4^{2 -}\). The \(SO_4^{2-}\) (sulfate ion) is a polyatomic ion.
• For \(MgCl_2\), it dissociates into \(Mg^{2+}\) and \(2Cl^{-}\). Both \(Mg^{2+}\) and \(Cl^{-}\) are monatomic ions.

Answer:

A. \(BaCO_3\), C. \(H_2SO_4\)