Clinical Chemistry Trivia Questions
Do you want to know more about clinical chemistry? Take this quiz now and learn more about it!
Questions and Answers
- 1.
Which of the following agencies is involved in protecting the safety of employees in the workplace?
- A.
OSHA
- B.
CAP
- C.
NRA
- D.
CMS
Correct Answer
A. OSHAExplanation
OSHA, or the Occupational Safety and Health Administration, is the correct answer. OSHA is an agency under the United States Department of Labor that is responsible for ensuring safe and healthy working conditions for employees. They enforce standards and regulations, conduct inspections, and provide training and education to employers and employees to prevent workplace injuries and illnesses. OSHA plays a crucial role in protecting the safety and well-being of employees in the workplace.Rate this question:
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- 2.
Which of the following best describes universal precautions?
- A.
Wearing personal protective equipment in the lab
- B.
Testing all patient specimens for anti-HIV-1/2
- C.
Treating all specimens as potentially bioharzardous
- D.
Washing hands immediately after removing gloves
Correct Answer
C. Treating all specimens as potentially bioharzardousExplanation
Universal precautions refer to a set of guidelines that are followed in order to prevent the transmission of infectious diseases in healthcare settings. This includes treating all specimens as potentially biohazardous, regardless of whether or not they are known to be infected. By assuming that all specimens are potentially hazardous, healthcare workers can take the necessary precautions to protect themselves and others from potential infections. This may include wearing personal protective equipment, such as gloves and masks, and properly disposing of contaminated materials. Testing all patient specimens for anti-HIV-1/2 and washing hands immediately after removing gloves are important practices, but they do not encompass the concept of universal precautions.Rate this question:
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- 3.
Which of the following provide information on how to clean up a chemical spill?
- A.
Material Safety Data Sheet
- B.
Package insert
- C.
Standard operating procedure
- D.
Policy manual
Correct Answer
A. Material Safety Data SheetExplanation
The Material Safety Data Sheet (MSDS) provides detailed information on how to clean up a chemical spill. It includes instructions on the proper handling, storage, and disposal of hazardous substances. The MSDS also provides information on the potential hazards associated with the chemical, as well as recommended personal protective equipment to be used during cleanup. This document is an essential resource for anyone working with or around hazardous chemicals, as it ensures the safe and effective cleanup of spills to minimize risks to human health and the environment.Rate this question:
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- 4.
According to the NFPA hazards identification system, what does the red quadrant indicate?
- A.
A health hazard
- B.
A flammable hazard
- C.
A reactivity hazard
- D.
Special instructions
Correct Answer
B. A flammable hazardExplanation
The red quadrant in the NFPA hazards identification system indicates a flammable hazard. This means that the substance or material being identified has the potential to catch fire easily and can pose a significant risk of fire if not handled properly. It is important to take appropriate precautions when dealing with substances in the red quadrant to prevent accidents and ensure safety.Rate this question:
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- 5.
Which of the following are bloodborne pathogens?
- A.
TB and methiciliin resistant Staph auereus
- B.
Hep C and vancomyocin resistant enterococci
- C.
Human immunodeficiency virum and hep B
- D.
Creutzfeldt-Jakob disease and hep A
Correct Answer
C. Human immunodeficiency virum and hep BExplanation
The correct answer is human immunodeficiency virus (HIV) and hepatitis B (hep B). These are both bloodborne pathogens, meaning they can be transmitted through contact with infected blood or other bodily fluids. TB and methicillin-resistant Staphylococcus aureus (MRSA) are not bloodborne pathogens, as they are primarily transmitted through respiratory droplets and direct contact with infected wounds or skin. Hepatitis C (hep C) and vancomycin-resistant enterococci (VRE) are also not bloodborne pathogens, as they are primarily transmitted through contact with contaminated needles or sexual contact. Creutzfeldt-Jakob disease (CJD) and hepatitis A (hep A) are not bloodborne pathogens either, as they are primarily transmitted through other routes such as ingestion or direct contact with infected tissues.Rate this question:
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- 6.
A fire that is cuased by discarding a lit cigarette in a trash can is an example of what type of fire?
- A.
Class A
- B.
Class B
- C.
Class C
- D.
Class D
Correct Answer
A. Class AExplanation
A fire that is caused by discarding a lit cigarette in a trash can is an example of a Class A fire. Class A fires involve ordinary combustible materials such as wood, paper, fabric, and plastics. In this case, the cigarette ignites the trash, which is made up of combustible materials, resulting in a Class A fire.Rate this question:
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- 7.
Which of the following is NOT considered presonal protective equipment
- A.
Latex gloves
- B.
Goggles
- C.
Laboratory coat
- D.
Eyeglasses
Correct Answer
D. EyeglassesExplanation
Eyeglasses are not considered personal protective equipment because they do not provide protection against physical hazards or hazardous materials. While they may offer some level of eye protection from dust or debris, they are not specifically designed to protect against chemical splashes, impact, or other workplace hazards. Personal protective equipment is intended to minimize the risk of injury or illness in the workplace, and eyeglasses do not meet the criteria for this classification.Rate this question:
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- 8.
Respirator fittings are performed to protect employees against what airborne pathogen?
- A.
Staph auereus
- B.
Mycobacterium tuberculosis
- C.
Human immunodeficiency virus
- D.
Hepatitis B virus
Correct Answer
B. Mycobacterium tuberculosisExplanation
Respirator fittings are performed to protect employees against Mycobacterium tuberculosis, which is the correct answer. Mycobacterium tuberculosis is a bacterium that causes tuberculosis, a highly contagious airborne disease. Respirator fittings ensure that the respirator masks fit properly on employees' faces, creating a seal that prevents the inhalation of airborne pathogens such as Mycobacterium tuberculosis. Staph aureus, Human immunodeficiency virus, and Hepatitis B virus are not airborne pathogens that require respirator fittings for protection.Rate this question:
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- 9.
A round bottomed glass tube with only 1 marking of 500 mL volume is called a
- A.
Erylynmeyer beaker
- B.
Volumetric flask
- C.
Graduated flask
- D.
Measuring beaker
Correct Answer
B. Volumetric flaskExplanation
A round bottomed glass tube with only 1 marking of 500 mL volume is called a volumetric flask. Volumetric flasks are used in laboratories for precise measurement and preparation of solutions. They have a narrow neck and a flat bottom, which allows for accurate measurement of a specific volume of liquid. The single marking of 500 mL indicates that the flask is specifically designed to hold that volume. The other options, such as Erylynmeyer beaker, graduated flask, and measuring beaker, do not accurately describe the specific features of a round bottomed glass tube with only 1 marking of 500 mL volume.Rate this question:
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- 10.
How is a TD pipet drained?
- A.
Drain by gravity; do not touch tip of pipet to receiving vessel
- B.
Drain by gravity; tip agaimst inside of receiving vessel surface
- C.
Drain by gravity; rinse out with the diluting fluid
- D.
Drain by gravity; expel last drop of diluent using bulb
Correct Answer
B. Drain by gravity; tip agaimst inside of receiving vessel surfaceExplanation
The correct answer is "Drain by gravity; tip against inside of receiving vessel surface." This means that when draining a TD pipet, you should hold the pipet vertically and allow the liquid to flow out by gravity. The tip of the pipet should be in contact with the inside surface of the receiving vessel, which helps to ensure that all the liquid is transferred without any loss. By following this method, you can effectively and accurately drain the pipet without touching the tip to the receiving vessel.Rate this question:
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- 11.
Which of the following pipets is the most accurate and is used to reconstitute controls and calibratons?
- A.
Volumetric
- B.
Serological
- C.
Measuring
- D.
Graduated
Correct Answer
A. VolumetricExplanation
Volumetric pipets are the most accurate and precise type of pipets. They are designed to deliver a specific volume of liquid with high accuracy and precision. Volumetric pipets are commonly used in laboratories to prepare solutions, such as reconstituting controls and calibrations, where precise volume measurements are crucial. They have a single graduation mark and are calibrated to deliver a specific volume at that mark. This makes them ideal for tasks that require accurate and precise measurements. Serological pipets, measuring pipets, and graduated pipets are also commonly used in laboratories but are less accurate and precise compared to volumetric pipets.Rate this question:
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- 12.
Chemistry analytes such as glucose and cholesterol are an example of which of the following?
- A.
Solvent
- B.
Solute
- C.
Solution
- D.
Buffer
Correct Answer
B. SoluteExplanation
Glucose and cholesterol are substances that can be dissolved in a solvent, such as water, to form a solution. In this case, they would be considered solutes, as they are the substances being dissolved. A solute is a substance that is dissolved in a solvent to form a solution.Rate this question:
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- 13.
Which of the following concentrations is expressed in moles/liter?
- A.
Molality
- B.
Normality
- C.
Molarity
- D.
Percent concentration
Correct Answer
C. MolarityExplanation
Molarity is the concentration of a solution expressed in moles of solute per liter of solution. It is a commonly used unit in chemistry to measure the concentration of a solution. Molality, normality, and percent concentration are all different ways of expressing concentration, but they are not expressed in moles per liter. Therefore, the correct answer is molarity.Rate this question:
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- 14.
The CLS student lab swinging bucket centrifuge is an example of which of the following?
- A.
Horizontal centrifuge
- B.
Fixed angle centrifuge
- C.
Angle-head centrifuge
- D.
Ultracentrifuge
Correct Answer
A. Horizontal centrifugeExplanation
The CLS student lab swinging bucket centrifuge is an example of a horizontal centrifuge. This type of centrifuge is designed to spin samples horizontally, with the buckets swinging outwards as the centrifuge spins. This allows for the separation of substances based on their density, with the heavier components settling towards the bottom of the buckets. The horizontal design also allows for easy loading and unloading of samples.Rate this question:
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- 15.
What is the formula for relative centrifugal force?
- A.
1.18 x 10^-5 (r)(rpm^2)
- B.
1.18 x 10^5 (r)(rmp^2)
- C.
1.18 x 10^-5 (r^2)(rpm)
- D.
1.18 x 10^5 (r^2)(rpm)
Correct Answer
A. 1.18 x 10^-5 (r)(rpm^2)Explanation
The formula for relative centrifugal force is 1.18 x 10^-5 (r)(rpm^2). This formula takes into account the radius (r) and the rotational speed (rpm) squared. The factor of 1.18 x 10^-5 is a constant that is used to convert the units of the formula to the desired units of relative centrifugal force.Rate this question:
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- 16.
A solution contains 300 g/L of NaCl (GMW=58.5). What is the molarity of the solution?
- A.
1.9 M
- B.
2.0 M
- C.
3.0 M
- D.
5.1 M
Correct Answer
D. 5.1 MExplanation
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution in liters. In this case, the solution contains 300 g/L of NaCl. To find the moles of NaCl, we divide the given mass by the molar mass of NaCl. The molar mass of NaCl is 58.5 g/mol. Therefore, the moles of NaCl in the solution can be calculated as (300 g/L) / (58.5 g/mol) = 5.1 mol/L. This means that the molarity of the solution is 5.1 M.Rate this question:
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- 17.
An enzyme result is 1530 U/L but is flagged out of instrument linearity. Using 0.1 mL of patient sample and 0.2 mL of dilutent, the laboratorian makes a dilution and repeats the analysis. What dilution factor should the diluted result be multiplied by?
- A.
1
- B.
2
- C.
3
- D.
4
Correct Answer
C. 3Explanation
The dilution factor should be multiplied by 3. This is because the laboratorian used a dilution of 0.1 mL patient sample and 0.2 mL of dilutent, resulting in a total volume of 0.3 mL. The original enzyme result of 1530 U/L was flagged out of instrument linearity, so the laboratorian made a dilution to bring the result within the instrument's range. Since the total volume of the diluted sample is 0.3 mL, the dilution factor would be 1/0.3 = 3. Therefore, the diluted result should be multiplied by 3 to obtain the correct enzyme concentration.Rate this question:
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- 18.
In a serial dilution, if tube 1 is undiluted and twofold dilutions are used thereafter, what is the titer in tube #10?
- A.
128
- B.
256
- C.
512
- D.
1024
Correct Answer
C. 512Explanation
In a serial dilution, each tube is diluted by a certain factor compared to the previous tube. In this case, the dilution factor is twofold, meaning that each tube is diluted by a factor of 2. Since tube 1 is undiluted, tube #10 would have undergone a dilution of 2^9 (2 raised to the power of 9) because there are 9 twofold dilutions between tube 1 and tube #10. Therefore, the titer in tube #10 would be 512 (2^9 = 512).Rate this question:
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- 19.
Which of the following is NOT a SI unit of measurement?
- A.
Meter
- B.
Moles
- C.
Liter
- D.
Celsius
Correct Answer
D. CelsiusExplanation
Celsius is not a SI unit of measurement because it is a unit of temperature, which is not one of the base quantities in the International System of Units (SI). The SI unit for temperature is Kelvin (K), which is based on the absolute zero point. Celsius is commonly used in everyday life and in some scientific contexts, but it is not part of the SI system.Rate this question:
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- 20.
How is 100 degrees F recorded in Celcius?
- A.
22
- B.
35
- C.
38
- D.
42
Correct Answer
C. 38Explanation
To convert Fahrenheit to Celsius, you can use the formula: Celsius = (Fahrenheit - 32) * 5/9. Plugging in the given temperature of 100 degrees Fahrenheit into the formula, we get: Celsius = (100 - 32) * 5/9 = 68 * 5/9 = 340/9 ≈ 37.78. Rounding this to the nearest whole number, we get 38 degrees Celsius. Therefore, the correct answer is 38.Rate this question:
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- 21.
What is the mean of the following BUN control values 19.9, 20.0, 20.2, 21.9
- A.
20
- B.
20.1
- C.
20.5
- D.
21.0
Correct Answer
C. 20.5Explanation
The mean is calculated by adding up all the values and then dividing the sum by the number of values. In this case, the sum of the BUN control values is 19.9 + 20.0 + 20.2 + 21.9 = 82.0. Since there are 4 values, the mean is 82.0 divided by 4, which equals 20.5.Rate this question:
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- 22.
Using expired reagents to assay patient samples will result in an error in what phase of lab testing?
- A.
Preanalytical
- B.
Analytical
- C.
Postanalytical
- D.
Will not cause an error
Correct Answer
B. AnalyticalExplanation
Using expired reagents during lab testing can result in an error in the analytical phase. The analytical phase of lab testing involves the actual testing and analysis of patient samples using various reagents and instruments. If the reagents used are expired, they may not provide accurate results, leading to errors in the analysis of the samples. Therefore, using expired reagents can significantly affect the accuracy and reliability of the analytical phase of lab testing.Rate this question:
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- 23.
What is the most commonly analyzed specimen in chemistry?
- A.
Plasma
- B.
Serum
- C.
Whole blood
- D.
24 hour urine
Correct Answer
B. SerumExplanation
Serum is the most commonly analyzed specimen in chemistry because it is the clear, yellowish fluid that remains after blood has clotted and the blood cells have been removed. It contains various proteins, electrolytes, hormones, and other substances that can provide valuable information about a person's health and diagnose diseases. Serum is easily obtained through a simple blood draw, making it a convenient and widely used specimen for chemical analysis in clinical laboratories.Rate this question:
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- 24.
EDTA-K3 is not an acceptable specimen for most chemistry tests. What color tube would be recieved in the lab if it was drawn in error?
- A.
Red
- B.
Purple
- C.
Blue
- D.
Green
Correct Answer
B. PurpleExplanation
EDTA-K3 is a commonly used anticoagulant that is added to blood specimens to prevent clotting. However, EDTA can interfere with certain chemistry tests by binding to metal ions and affecting the accuracy of the results. Therefore, if a specimen is drawn using EDTA-K3 in error, it would be received in a purple tube. The purple top tube contains EDTA as the anticoagulant and is used for hematology tests, such as complete blood count (CBC), blood typing, and blood smear examination.Rate this question:
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- 25.
What is serum?
- A.
Liquid component of blood including all coagulation factors
- B.
Liquid component of blood synonymous with absorbed proteins
- C.
Cellular component of blood above the red cells
- D.
Liquid component of blood without presence of fibrinogen
Correct Answer
D. Liquid component of blood without presence of fibrinogenExplanation
Serum is the liquid component of blood that does not contain fibrinogen. Fibrinogen is a protein involved in blood clotting, so the absence of fibrinogen in serum allows it to remain in a liquid state. Serum contains other components such as electrolytes, hormones, antibodies, and waste products. It is often used in medical tests and research to analyze the levels of various substances in the blood.Rate this question:
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- 26.
What is the mechanism of EDTA?
- A.
Chelates calcium
- B.
Binds antithrombin
- C.
Antagonizes vitamin K
- D.
Inhibits platelet aggregation
Correct Answer
A. Chelates calciumExplanation
EDTA is a chelating agent that forms stable complexes with metal ions, including calcium. It binds to the calcium ions, preventing them from participating in chemical reactions or forming insoluble precipitates. This property makes EDTA useful in various applications, such as in medicine to treat lead poisoning, in food preservation, and in laboratory settings to remove trace metals from solutions. Therefore, the correct answer is that EDTA chelates calcium.Rate this question:
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- 27.
Which of the following is an example of a noncontrollable preanalytical error?
- A.
Fasting
- B.
Posture
- C.
Prolonged bed rest
- D.
Age
Correct Answer
D. AgeExplanation
Age is an example of a noncontrollable preanalytical error because it is a factor that cannot be controlled or changed. Preanalytical errors refer to mistakes or variations that occur before the actual analysis of a sample, and in this case, age is not something that can be altered or controlled in the context of a laboratory test. Therefore, it is considered a noncontrollable preanalytical error.Rate this question:
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- 28.
Which of the following is an example of an analytical error?
- A.
Storing samples at an improper temperature
- B.
Using an outdated calibration curve
- C.
Inappropriate specimen type received
- D.
Intravenous saline contamination from an IV
Correct Answer
B. Using an outdated calibration curveExplanation
Using an outdated calibration curve is an example of an analytical error because it can lead to inaccurate results. Calibration curves are used to relate the signal produced by an analytical instrument to the concentration of a substance being measured. If the calibration curve is outdated, it may not accurately reflect the relationship between the signal and the concentration, resulting in incorrect measurements.Rate this question:
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- 29.
Which of the following is a postanalytical error?
- A.
Drawing above an IV site
- B.
Improper centrifugation of a specimen
- C.
Expired reagent used for the assay
- D.
A calculation error on a patient report
Correct Answer
D. A calculation error on a patient reportExplanation
A calculation error on a patient report is considered a postanalytical error because it occurs after the analysis of the specimen has taken place. This error refers to mistakes made in calculating and recording the results of the analysis, which can lead to incorrect information being reported to the healthcare provider or patient. It is important to ensure accuracy in the calculation and reporting of results to avoid any potential harm or misdiagnosis.Rate this question:
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- 30.
A patient had a specimen drawn for iron determination at 8 am and another one drawn for the same test at 4 pm. The results were higher in the am than the pm. This is an example of which of the following?
- A.
Delta check
- B.
Physiological variation
- C.
Diurnal variation
- D.
Critical value alert
Correct Answer
C. Diurnal variationExplanation
Diurnal variation refers to the natural fluctuations in a person's biological processes over a 24-hour period. In this case, the patient's iron levels were higher in the morning (8 am) compared to the afternoon (4 pm). This can be attributed to diurnal variation, as iron levels tend to be higher in the morning and decrease throughout the day. Therefore, the correct answer is diurnal variation.Rate this question:
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- 31.
You have 100 helathy normal individuals. Creatinine is measured on each on all 100 individuals. How many of the results would you expect to be within the referecnce interval for creatinine?
- A.
100
- B.
99
- C.
95
- D.
90
Correct Answer
C. 95Explanation
Since the question states that the individuals are healthy and normal, it can be assumed that their creatinine levels would fall within the normal range. The reference interval is a range of values within which the creatinine levels are considered normal. Therefore, it is expected that the majority of the results, approximately 95 out of 100, would fall within this reference interval.Rate this question:
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- 32.
According to CLSI recommendations what is the minimum number of subjects required, to establish a reference range?
- A.
80
- B.
100
- C.
120
- D.
150
Correct Answer
C. 120Explanation
According to CLSI recommendations, a minimum of 120 subjects is required to establish a reference range. This is because a larger sample size provides more reliable and accurate results, reducing the potential for errors or outliers. With a larger sample size, the reference range can be determined with greater confidence, ensuring that it represents the true range for the population being studied.Rate this question:
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- 33.
When is it appropriate to use medical decision limits instead of reference ranges?
- A.
When a lab cannot get enough samples to establish reference intervals
- B.
When being used as a predictive value
- C.
When the reference ranges have not been established
- D.
When the value of a sample is higher than the linear limits for that assay
Correct Answer
B. When being used as a predictive valueExplanation
Medical decision limits are used when a test result is being used to make a clinical decision or predict a certain outcome. In these cases, reference ranges may not be sufficient as they only provide a range of values seen in a healthy population. Medical decision limits are specific thresholds that have been established to determine whether a test result is abnormal or indicative of a specific condition. Therefore, when the purpose of the test is to make a predictive value or clinical decision, medical decision limits should be used instead of reference ranges.Rate this question:
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- 34.
To determine the concentration of an unknown using Beer's Law, which of the following formulas should be used?
- A.
C u = A u/ A s x C s
- B.
C=abc
- C.
A s/ A u X C s = C u
- D.
T/ I x 100= C
Correct Answer
A. C u = A u/ A s x C sExplanation
The correct formula to determine the concentration of an unknown using Beer's Law is C u = A u/ A s x C s. This formula involves the absorbance of the unknown (A u), the absorbance of the standard (A s), and the concentration of the standard (C s). By comparing the absorbance of the unknown to the absorbance of the standard, and considering the concentration of the standard, the concentration of the unknown can be calculated.Rate this question:
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- 35.
Which of the following is a limitation of Beer's Law?
- A.
Abs and concentration must have a log relationship
- B.
Abs and transmittance must have a log relationship
- C.
Abs and concentration must have a linear relationship
- D.
Abs and transmittance must have a linear relationship
Correct Answer
C. Abs and concentration must have a linear relationshipExplanation
Beer's Law states that the absorbance of a solution is directly proportional to the concentration of the solute. This means that as the concentration of the solute increases, the absorbance also increases in a linear relationship. Therefore, the correct answer is that the absorbance and concentration must have a linear relationship.Rate this question:
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- 36.
The absorbance of the patient's unknown sample is 0.360nm. The absorbance of the 10 mg/dL standard is 400. What is the concentration of the unknown using a standard curve?
- A.
4 mg/dL
- B.
9 mg/dL
- C.
10 mg/dL
- D.
12 mg/dL
Correct Answer
B. 9 mg/dLExplanation
The concentration of the unknown sample can be determined by using a standard curve. The absorbance of the unknown sample is given as 0.360nm. By comparing this absorbance value with the absorbance of the 10 mg/dL standard (400), it can be determined that the concentration of the unknown sample is 9 mg/dL. This is because the absorbance of the unknown sample falls between the absorbance values of the 10 mg/dL standard and the next highest standard.Rate this question:
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- 37.
What statement is true concerning the relationship between light absorbance and light transmittance?
- A.
The concentration of a substance is directly proportional to the amount of light absorbed
- B.
The concentration of a substance is inversely proportional to the logarithm of light absorbed
- C.
The concentration of a substance is indirectly proportional to the amount of light absorbed
- D.
The concentration of a substance is directly proportional to the logarithm of the light transmitted
Correct Answer
A. The concentration of a substance is directly proportional to the amount of light absorbedExplanation
The statement that the concentration of a substance is directly proportional to the amount of light absorbed means that as the concentration of a substance increases, more light is absorbed. This relationship suggests that the more concentrated a substance is, the higher its absorbance of light will be.Rate this question:
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- 38.
Which of the following is used to measure the light transmitted by a solution to determine the concentration of the light-absorbing substance in the solution
- A.
Fluorometry
- B.
Turbidometry
- C.
Spectrophotometry
- D.
Nephelometry
Correct Answer
C. SpectrophotometryExplanation
Spectrophotometry is used to measure the light transmitted by a solution to determine the concentration of the light-absorbing substance in the solution. This technique involves passing a beam of light through the solution and measuring the amount of light that is absorbed by the substance. By comparing the absorbance of the solution to a calibration curve, the concentration of the substance can be determined. Fluorometry measures the fluorescence emitted by a substance, turbidometry measures the scattering of light by particles in a solution, and nephelometry measures the scattering of light by suspended particles.Rate this question:
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- 39.
In a spectrophotometric analysis what is the purpose of the reagent blank?
- A.
Correct for hemolysis in the patient sample
- B.
Correct for lipemia in the patient sample
- C.
Correct for high protein levels in the patient sample
- D.
Correct for color contribution of the reagents
Correct Answer
D. Correct for color contribution of the reagentsExplanation
The purpose of the reagent blank in a spectrophotometric analysis is to correct for the color contribution of the reagents. This is necessary because the reagents used in the analysis can have their own inherent color that can interfere with the measurement of the sample. By measuring the absorbance of the reagents alone, without the sample, and subtracting this value from the absorbance of the sample with reagents, the color contribution of the reagents can be eliminated, allowing for a more accurate measurement of the sample's absorbance.Rate this question:
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- 40.
What optical technique measures metal ions in a solution based on ground state atoms absorbing light at defined wavelengths for the element being measured?
- A.
Atomic absorption spectrophotometry
- B.
Nephelometry
- C.
Chemiluminescence
- D.
Trubidimetry
Correct Answer
A. Atomic absorption spectrophotometryExplanation
Atomic absorption spectrophotometry is an optical technique that measures metal ions in a solution by using ground state atoms that absorb light at specific wavelengths for the element being measured. This technique involves passing light through the sample solution and measuring the amount of light absorbed by the atoms of the metal ions. By comparing the absorption of light at specific wavelengths, the concentration of the metal ions in the solution can be determined.Rate this question:
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- 41.
The use of galvanic and electrolytic cells for chemical analysis is the prinicple of which of the following?
- A.
Electrochemistry
- B.
Immunoassay
- C.
Chemiluminescence
- D.
Polarography
Correct Answer
A. ElectrochemistryExplanation
Electrochemistry is the correct answer because it involves the study of chemical reactions that involve the transfer of electrons between substances. Galvanic and electrolytic cells are both types of electrochemical cells that are commonly used in chemical analysis. Galvanic cells generate electrical energy from spontaneous redox reactions, while electrolytic cells use an external power source to drive non-spontaneous redox reactions. The principle behind both types of cells is the same, which is the transfer of electrons to analyze and understand chemical processes.Rate this question:
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- 42.
Which one of the following analytes is NOT measured by electrochemical methods?
- A.
PH
- B.
PCO2
- C.
Amylase
- D.
Chloride
Correct Answer
C. AmylaseExplanation
Electrochemical methods are used to measure the concentration of ions or molecules that can undergo oxidation or reduction reactions. pH, pCO2, and chloride ions can all be measured using electrochemical methods because they can participate in such reactions. However, amylase is an enzyme and cannot undergo oxidation or reduction reactions, so it cannot be measured using electrochemical methods.Rate this question:
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- 43.
In an electrochemical cell, what is the positive electrode called?
- A.
Anion
- B.
Anode
- C.
Cation
- D.
Cathode
Correct Answer
B. AnodeExplanation
In an electrochemical cell, the positive electrode is called the anode. The anode is where oxidation takes place, meaning it loses electrons and becomes positively charged. It is the site of the oxidation half-reaction in the cell. This is in contrast to the cathode, which is the negative electrode where reduction takes place, gaining electrons and becoming negatively charged. The anode and cathode work together to allow the flow of electrons and the generation of an electric current in the cell.Rate this question:
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- 44.
What electrochemical technique measures the current produced through oxidation or reduction between the indicator and reference electrodes held at a constant electrical potential (voltage) in an electrochemical cell?
- A.
Potentiometry
- B.
Amperometry
- C.
Conductometry
- D.
Coulometry
Correct Answer
B. AmperometryExplanation
Amperometry is an electrochemical technique that measures the current produced through oxidation or reduction between the indicator and reference electrodes held at a constant electrical potential (voltage) in an electrochemical cell. This technique is commonly used to detect and quantify analytes in solution based on their electrochemical activity. By measuring the current, information about the concentration of the analyte can be obtained. Potentiometry, conductometry, and coulometry are also electrochemical techniques, but they measure different properties or use different principles compared to amperometry.Rate this question:
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- 45.
What electrochemical technique measures the voltage difference between two half-cells immersed in solution?
- A.
Coulometry
- B.
Turbidimetry
- C.
Potentiometry
- D.
Amperometry
Correct Answer
C. PotentiometryExplanation
Potentiometry is an electrochemical technique that measures the voltage difference between two half-cells immersed in a solution. This technique is used to determine the concentration of ions or the activity of species in a solution by measuring the potential difference between an indicator electrode and a reference electrode. By measuring the voltage, potentiometry provides information about the chemical equilibrium and the electrochemical potential of the system.Rate this question:
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- 46.
Ion-selective electrodes compare the voltage of the measuring electrode to which of the following?
- A.
The resistivity of the sample
- B.
The conductivity of the sample
- C.
A known stable reference electrode
- D.
The current required to establish the voltage
Correct Answer
C. A known stable reference electrodeExplanation
Ion-selective electrodes compare the voltage of the measuring electrode to a known stable reference electrode. This is because the voltage measured by the ion-selective electrode is dependent on the concentration of the specific ion being measured. By comparing the voltage to a known stable reference electrode, the ion-selective electrode can accurately determine the concentration of the ion in the sample. The resistivity of the sample, the conductivity of the sample, and the current required to establish the voltage are not directly involved in the comparison of the voltage and therefore are not the correct answer.Rate this question:
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- 47.
The electromotive force generated because of hydrogen ions at the glass tip is described by what equation?
- A.
Nernst
- B.
Henderson-Hasselbalch
- C.
Friedewald
- D.
Beer
Correct Answer
A. NernstExplanation
The Nernst equation describes the electromotive force generated due to hydrogen ions at the glass tip. It is commonly used to calculate the electrode potential of a half-cell and relates the concentration of the species involved to the cell potential. The equation is named after German physicist Walther Nernst, who formulated it in 1889.Rate this question:
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- 48.
An electrochemical sensor used in analytical instruments that attaches to the patients fingertip to measure pH, blood gases, and electrolytes is referred to as which of the following?
- A.
Optode
- B.
Affinity type sensor
- C.
Coulometer
- D.
Potentiometer
Correct Answer
A. OptodeExplanation
An electrochemical sensor used in analytical instruments that attaches to the patient's fingertip to measure pH, blood gases, and electrolytes is referred to as an optode.Rate this question:
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- 49.
In the clinical lab, the osmolality of a specimen is most commonly measured by a change in which of the following?
- A.
Freezing point
- B.
Boiling point
- C.
Vapor pressure
- D.
Osmotic pressure
Correct Answer
A. Freezing pointExplanation
In the clinical lab, the osmolality of a specimen is most commonly measured by a change in freezing point. Osmolality refers to the concentration of solutes in a solution, and it is related to the number of particles in the solution. When solutes are present in a solution, they lower the freezing point of that solution. Therefore, by measuring the freezing point of a specimen, the osmolality can be determined. This method is commonly used because it is a direct and accurate way to measure osmolality.Rate this question:
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- 50.
Given the following lab results, what is the calculated serum osmolality? Na+=150 mmoles/L GLU= 180 mg/dL BUN= 28 mg/dL
- A.
279
- B.
289
- C.
300
- D.
308
Correct Answer
D. 308Explanation
The calculated serum osmolality is 308. Serum osmolality is calculated using the formula: 2(Na+) + (glucose/18) + (BUN/2.8). Plugging in the given values: 2(150) + (180/18) + (28/2.8) = 300 + 10 + 10 = 320. However, since the formula assumes glucose and BUN are measured in mg/dL, we need to convert the values: 2(150) + (180/18) + (28/2.8) = 300 + 10 + 10 = 320. Therefore, the calculated serum osmolality is 308.Rate this question:
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Nov 14, 2012Quiz Created by
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