If an aqueous solution of is added to a mixture of barium nitrate and silver nitrate, the barium ion will precipitate, but the silver ion would remain in solution.

sodium fluoride

Explanation:

When we add sodium fluoride to a solution of a given mixture, we get barium fluoride from Ba, which would be an insoluble salt, and silver fluoride from Ag, which would be a soluble salt. 

The solubility rule will be used to determine the barium salt that forms as a precipitate and leaves Ag+ salt in the solution.

From the following equations, we will see that the precipitate is formed in Ba but Ag remains dissolved in the solution.

its first and third is your answer i did the qustion the fourth isnt right

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