Final answer:
The correct answer is option b. If you have excess magnesium ribbon at the end of the reaction, it does not necessarily mean that HCl was completely consumed. A titration is required to accurately measure the amount of hydrochloric acid that reacted.
Step-by-step explanation:
The statement is False. If you have excess magnesium ribbon at the end of the reaction, it does not necessarily mean that HCl was completely consumed. In a chemical reaction between hydrochloric acid (HCl) and magnesium (Mg), magnesium reacts with hydrochloric acid to form magnesium chloride (MgCl2) and hydrogen gas (H2).
If you have excess magnesium ribbon, it means that there was an excess of magnesium, not that the hydrochloric acid was completely consumed. To determine if HCl was completely consumed, you would need to perform a titration to accurately measure the amount of hydrochloric acid that reacted.
Titration is a technique used to determine the concentration of a solution by reacting it with a solution of known concentration. By measuring the amount of the known solution required to react completely with the unknown solution, you can determine the concentration of the unknown solution.