Chapter 1

What is the molarity for a solution containing \(100 \mathrm{~g}\) of \(\mathrm{NaCl}\) made up to 500 mL with distilled water? Assume a gram molecular weight (from periodic table) of approximately 58 grams. a. \(3.45 \mathrm{M}\) b. \(1.72 \mathrm{M}\) c. \(290 \mathrm{M}\) d. \(5.27 \mathrm{M}\)

What is the dilution factor for a solution containing \(100 \mathrm{~g}\) of \(\mathrm{NaCl}\) made up to \(500 \mathrm{~mL}\) with distilled water? a. \(1: 5\) or \(1 / 5\) b. 5 c. 50 or \(1 / 50\) d. 10

You must make \(1 \mathrm{~L}\) of \(0.2 \mathrm{M}\) acetic acid \(\left(\mathrm{CH}_{3} \mathrm{COOH}\right)\). All you have available is concentrated glacial acetic acid (assay value, \(98 \%\); specific gravity, \(1.05\) \(\mathrm{g} / \mathrm{mL}\) ). It will take milliliters of acetic acid to make this solution. Assume a gram molecular weight of \(60.05\) grams. a. \(11.7\) b. \(1.029\) c. \(3.42\) d. \(12.01\)

What is the hydrogen ion concentration of an acetate buffer having a pH of \(3.85\) ? a. \(1.41 \times 10^{-4}\) b. \(\quad 3.90 \times 10^{-1}\) c. \(0.048\) d. \(0.15 \times 10^{-6}\)

Using the Henderson-Hasselbalch equation, give the ratio of salt to weak acid for a Veronal buffer with a \(\mathrm{pH}\) of \(8.6\) and a \(\mathrm{p} K_{\mathrm{a}}\) of \(7.43 .\) a. \(14.7 / 1\) b. \(1 / 8.6\) c. \(1.17 / 1\) d. \(1 / 4.3\)

The \(\mathrm{pK}_{\mathrm{a}}\) for acetic acid is \(4.76 .\) If the concentration of salt is \(2 \mathrm{mmol} / \mathrm{L}\) and that of acetic acid is \(6 \mathrm{mmol} / \mathrm{L}\), what is the expected \(\mathrm{pH}\) ? a. \(4.43\) b. \(6.19\) c. 104 d. 56

The hydrogen ion concentration of a solution is \(0.000439\). What is the \(\mathrm{pH}\) ? a. \(3.36\) b. \(4.39 \times 10^{-5}\) c. \(4.39\) d. \(8.03\)

A 24-hour urine has a total volume of 1,200 mL. A 1:200 dilution of the urine specimen gives a creatinine result of \(0.8 \mathrm{mg} / \mathrm{dL}\). The serum value is \(1.2 \mathrm{mg} / \mathrm{dL}\). What is the final value of creatinine in \(\mathrm{mg} / \mathrm{dL}\) in the undiluted urine sample? a. 160 b. \(0.8\) c. 960 d. 860

A 24-hour urine has a total volume of 1,200 mL. A \(1: 200\) dilution of the urine specimen gives a creatinine result of \(0.8 \mathrm{mg} / \mathrm{dL}\). The serum value is \(1.2 \mathrm{mg} / \mathrm{dL}\). What is the result in terms of grams per 24 hours? a. \(1.92\) b. \(0.08\) c. 80 d. 19

A new medical technologist was selecting analyte standards to develop a standard curve for a high- performance liquid chromatography (HPLC) procedure. This analyte must have a \(100 \%\) purity level and must be suitable for HPLC. Which of the following labels would be most appropriate for this procedure? a. ACS with no impurities listed b. USP c. NF d. \(\mathrm{CP}\) e. ACS with impurities listed

When selecting quality control reagents for measuring an analyte in urine, the medical technologist should select: a. A quality control reagent prepared in a urine matrix. b. A quality control reagent prepared in a serum matrix. c. A quality control reagent prepared in deionized water. d. The matrix does not matter; any quality control reagent as long as the analyte of measure is chemically pure.

True or False? Laboratory liquid-in-glass thermometers should be calibrated against an NIST-certified thermometer.

Which of the following containers is calibrated to hold only one exact volume of liquid? a. Volumetric flask b. Erlenmeyer flask c. Griffin beaker d. Graduated cylinder

Which of the following does NOT require calibration in the clinical laboratory? a. Electronic balance b. Liquid-in-glass thermometer c. Centrifuge d. Volumetric flask e. Air-displacement pipette

Which of the following errors is NOT considered a preanalytical error? a. During a phlebotomy procedure, the patient is opening and clenching his fist multiple times. b. The blood was not permitted to clot and spun in a centrifuge after 6 minutes of collection. c. The patient was improperly identified leading to a mislabeled blood sample. d. The serum sample was diluted with tap water. e. During phlebotomy, the EDTA tube was collected prior to the red clot tube.