Identify the solutions that will form a precipitate when mixed with aqueous barium chloride, BaCl2 (aq). Select all that apply.

The given question is incomplete, the complete question is:

Identify the solutions that will form a precipitate when mixed with aqueous barium chloride, BaCl2 (aq). Select all that apply. potassium carbonate, K2CO3 (aq) silver nitrate, AgNO3(aq) sulfuric acid, H2SO4 (aq) sodium hydroxide, NaOH(aq) sodium chloride, NaCl (aq) copper(II) nitrate, Cu(NO3)2 (aq)

The aqueous solution of BaCl2 form precipitate with potassium carbonate, silver nitrate, sulfuric acid and sodium hydroxide.

Explanation:

The formation of an insoluble salt, which takes place when two solutions comprising soluble salts are reacted with each other, the reaction is termed as precipitation reaction. The insoluble salt produced in the given reaction is termed as the precipitate.  

BaCl₂ reacts with K₂CO₃ to produce white precipitate in the form of BaCO₃,  

BaCl₂ (aq) + K₂CO₃ (aq) ⇒ BaCO₃ (s) + 2KCl (aq)

BaCl₂ reacts with H₂SO₄ to produce white precipitate in the form of BaSO₄,  

BaCl₂ (aq) + H₂SO₄ (aq) ⇒ BaSO₄ (s) + 2HCl (aq)

BaCl₂ (aq) reacts with NaOH to produce white precipitate in the form of Ba(OH)2,  

BaCl₂ (aq) + 2NaOH (aq) ⇒ Ba(OH)2 (s) + 2NaCl (aq)

BaCl₂ reacts with AgNO₃ to produce white precipitate in the form of 2AgCl (s),  

BaCl₂ (aq) + 2AgNO₃ (aq) ⇒ Ba(NO₃)₂ (aq) + 2AgCl (s)

Upon reaction of BaCl₂ with Cu(NO₃)₂ no formation of precipitate takes place, and BaCl₂ does not react with NaCl.  

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.