Chm/109 week 7

Prepare written answers to the following exercises:

1.     Adapted from Exercise 106 in Ch. 14 of Introductory Chemistry:

Imagine that you are a charge nurse in a nursing home. You are typically the only medical personnel in the house at any one time. A patient who is known to have excess stomach acid asks you to give him an antacid tablet. The typical antacid is either calcium carbonate or magnesium carbonate. The antacid tablet that you stock requires 25.82 mL of 0.200 M HCl to titrate to its equivalence point. Assume that stomach acid has a pH of 1.1. Also, suppose that the patient’s size and weight indicate that his stomach will hold approximately 140 mL of stomach acid.

·         How many antacid tablets should you give him if you want to neutralize all his stomach acid?

·         Explain your rationale for your answer. Include the balanced equation you used to determine your answer.

Imagine that you are a geologist trying to determine the amount of iron in the samples of rocks in a mountain side. A typical reaction used to determine the amount of iron in a sample is to combine it in a reaction with permanganate ion, MnO4-, with Fe2+ in an acidic solution. The skeleton reaction is: MnO₄^–(aq) + Fe²⁺(aq) à Mn²⁺(aq) + Fe³⁺(aq)

·         Write the half reactions for this reaction.

·         Write the balanced equation for this reaction.