HESI A2 Chemistry case studies
HESI A2 Chemistry · Put your knowledge to work in context.
The HESI A2 Chemistry test is one of the subject-area modules in the HESI Admission Assessment (A2), a battery of tests that many nursing and health-science programs in the United States use as part of their admissions review. Candidates are typically prospective nursing students, transfer applicants, or pre-nursing students who must demonstrate readiness in core science before enrolling in a program's science sequence. The HESI A2 Chemistry case studies are 5 cases and about 3,334 words.
1The Volumetric Flask: Density, Significant Figures, and What Counts as a Mixture
During a lab practical, a nursing student is given three items on a tray: a sealed 25.0 mL volumetric flask holding a clear, colorless liquid; a 500 mL bag labeled 0.90% sodium chloride in water; and a beaker of the same salt water that has been boiled down to roughly half its original volume. The empty flask weighed 18.42 g, and the filled flask weighs 44.72 g on the same balance.
688 words, about 3 min2Same Element, Different Nucleus: Explaining Iodine-131 to a Patient
A 47-year-old patient with Graves disease is scheduled for radioiodine therapy. The nuclear pharmacy delivers a capsule of iodine-131, and the chart notes that the stable iodine in iodized salt is iodine-127.
675 words, about 3 min3CaCl2 or Ca(ClO)2? A Shelf Check That Cannot Be Guessed
A hospital pharmacy technician is checking a shipment against an order for calcium chloride 10% injection, used to treat hypocalcemia. One stock bottle is labeled CaCl2.
632 words, about 3 min4Compounding 500 mL of 0.90% Saline from 23.4% Stock
A nurse on a pediatric floor needs 500 mL of 0.90% w/v sodium chloride irrigation, but the unit stocks only 23.4% w/v sodium chloride concentrate and sterile water. The pharmacist approves the dilution if the calculation is documented.
665 words, about 3 min5Two Antacid Tablets and 50 mL of Gastric Acid
A patient with reflux chews two antacid tablets, each containing 500 mg of calcium carbonate as the only active ingredient, and asks the nurse, 'Does this get rid of all the acid in my stomach?' A unit reference states that the fasting stomach holds about 50 mL of gastric fluid with hydrochloric acid at roughly 0.10 M. The nurse decides to answer quantitatively, using molar masses of 100.09 g/mol for CaCO3, 36.46 g/mol for HCl, and 44.01 g/mol for CO2.
674 words, about 3 min