Question

in part iv, \determining the percent sulfate,\ you add barium nitrate to a solution of your alum. this causes a white precipitate to form. what is the chemical identity of this precipitate? select one. potassium nitrate barium hydroxide barium aluminate barium sulfate (baso4)

Explanation:

When barium nitrate ($Ba(NO_3)_2$) reacts with sulfate - containing compounds (alum has sulfate ions in its formula), a double - displacement reaction occurs. The barium ions ($Ba^{2 + }$) combine with sulfate ions ($SO_4^{2 - }$) to form barium sulfate ($BaSO_4$), which is a white precipitate. Barium aluminate would require the presence of aluminate ions in a different reaction context. Barium hydroxide would form if there were hydroxide - related reactants. Potassium nitrate is a soluble salt and not a precipitate in this context.

Answer:

Barium sulfate ($BaSO_4$)