Final answer:
A precipitate of AgCl (silver chloride) is formed when 1.0 M AgNO₃ is combined with 1.0 M HCl, due to a double replacement reaction.
Step-by-step explanation:
When 1.0 M AgNO₃ is combined with 1.0 M HCl, the silver ions (Ag+) from silver nitrate react with the chloride ions (Cl−) from hydrochloric acid to form a precipitate of AgCl (silver chloride). This is a common double replacement reaction that occurs in aqueous solution resulting in the precipitation of an insoluble salt:
AgNO₃(aq) + HCl(aq) → AgCl(s) + HNO₃(aq)
Therefore, the correct answer to the student's question is:
d) A precipitate of AgCl is formed.