Which of the following pairs of compounds would form a precipitate when their aqueous solutions are mixed?

A.

NaCl and KNO\(_{3}\)

B.

KCL and NaNO\(_{3}\)

C.

K\(_{2}\)SO\(_{4}\) and BaCl\(_{2}\)

D.

NH\(_{4}\)NO\(_{3}\) and CO\(_{3}\)

Correct answer is C

when potassium sulfate is mixed with barium chloride a white precipitate of barium sulfate will be form. barium sulfate is slightly soluble in water, so it will precipitate out as a solid

BaCl2 + K2SO4 → BaSO4 + 2KCl 

note; all substances are aqueous except BaSO4 which is solid