Science Homework Help

 4. Identify which of the possible unknowns for this experiment would give the following

behavior.

×       A clear, colorless solution of the unknown tested acidic to indicator paper.

×       Testing with indicator paper indicate that the solution had an acidic pH. 

×       Nothing was observed when KOH was added to the first test tube.

×       Nothing was observed when AgNO3(aq) was added to the second test tube.

×       A white precipitate formed when BaCl2(aq) was added to the third test tube.

 (Note that under the conditions used in our lab experiment, Ag2SO4 does not form a precipitate.) come up with a balanced molecular equation including states of matter for the reaction observed between this compound and BaCl2.

5. Identify which of the possible unknowns for this experiment would give the following behavior.

×       A clear, blue solution of the unknown tested acidic to indicator paper.

×       There was no reaction when this unknown was tested with either AgNO3(aq), dilute H2SO4, or BaCl2(aq).

×       A black precipitate was formed when the unknown was treated with Na2S(aq).

×       A pale blue precipitate was formed when the unknown was treated with KOH(aq).

come up with a a balanced molecular equation including states of matter for the reactions observed with Na2S and KOH.

6. Which reagent available in this experiment will distinguish between a soluble Cl- salt solution and a soluble NO3- salt solution? Explain your reasoning.