Podcast
Questions and Answers
What is the molarity of a solution containing 1 mole of KCl in 1 L of solution?
What is the molarity of a solution containing 1 mole of KCl in 1 L of solution?
1 M
What is the molarity of a solution of NaCl when 58.5 g of NaCl are dissolved in 0.50 L of solution?
What is the molarity of a solution of NaCl when 58.5 g of NaCl are dissolved in 0.50 L of solution?
If 1.5 moles of NaOH are dissolved in 500 mL of H2O, what is the molarity?
If 1.5 moles of NaOH are dissolved in 500 mL of H2O, what is the molarity?
3.0 M
How many grams of NaOH are present in 250 mL of a 0.15 M NaOH solution?
How many grams of NaOH are present in 250 mL of a 0.15 M NaOH solution?
Signup and view all the answers
How many liters of 0.75 M NaOH can be prepared from 20 g of NaOH?
How many liters of 0.75 M NaOH can be prepared from 20 g of NaOH?
Signup and view all the answers
What is the osmolarity of a 0.30 molar solution of NaOH?
What is the osmolarity of a 0.30 molar solution of NaOH?
Signup and view all the answers
How many grams of CaCl2 would you need to prepare 500 mL of a solution with an osmolarity of 0.50?
How many grams of CaCl2 would you need to prepare 500 mL of a solution with an osmolarity of 0.50?
Signup and view all the answers
How would you prepare 0.35 L of 6.5% (w/v) NaOH?
How would you prepare 0.35 L of 6.5% (w/v) NaOH?
Signup and view all the answers
How many mL of 95% ethanol would you need to prepare 500 mL of 70 % ethanol?
How many mL of 95% ethanol would you need to prepare 500 mL of 70 % ethanol?
Signup and view all the answers
If you added water to 50 mL of 25% isopropanol to a total volume of 250 mL, what would the concentration of the new solution be?
If you added water to 50 mL of 25% isopropanol to a total volume of 250 mL, what would the concentration of the new solution be?
Signup and view all the answers
What is the pH of a 0.01 mol/L HCl solution?
What is the pH of a 0.01 mol/L HCl solution?
Signup and view all the answers
What is the pOH of a 0.02 mol/L NaOH solution?
What is the pOH of a 0.02 mol/L NaOH solution?
Signup and view all the answers
If the pH of a solution is 2, what is the pOH?
If the pH of a solution is 2, what is the pOH?
Signup and view all the answers
Molality and osmolality are both methods of expressing concentration of solutions based on volume.
Molality and osmolality are both methods of expressing concentration of solutions based on volume.
Signup and view all the answers
A 1 molal (1 m) solution contains 1 mole of solute plus 1000 g of solvent. How many moles of solute are present in a 1 molal solution?
A 1 molal (1 m) solution contains 1 mole of solute plus 1000 g of solvent. How many moles of solute are present in a 1 molal solution?
Signup and view all the answers
What is the osmolality of a solution?
What is the osmolality of a solution?
Signup and view all the answers
How would you prepare 1.00 kg of 0.200 molal Na2CO3?
How would you prepare 1.00 kg of 0.200 molal Na2CO3?
Signup and view all the answers
Calculate the osmolality of 35 g NaCl dissolved in 1500 g of H2O?
Calculate the osmolality of 35 g NaCl dissolved in 1500 g of H2O?
Signup and view all the answers
A patient sample was diluted 1/5 with serum diluent and then tested for sodium. The sodium concentration of the diluted sample was determined to be 28 mmol/L. What is the concentration of sodium in the original patient sample?
A patient sample was diluted 1/5 with serum diluent and then tested for sodium. The sodium concentration of the diluted sample was determined to be 28 mmol/L. What is the concentration of sodium in the original patient sample?
Signup and view all the answers
What is the total dilution in tube #5 of a serial dilution if 9.0 mL of diluent is placed in the first tube and 2.0 mL of diluent in each successive tube, and 1.0 mL of serum is added to the first tube and mixed, and 1.0 mL of the mixture in the first tube is serially diluted through the remaining tubes?
What is the total dilution in tube #5 of a serial dilution if 9.0 mL of diluent is placed in the first tube and 2.0 mL of diluent in each successive tube, and 1.0 mL of serum is added to the first tube and mixed, and 1.0 mL of the mixture in the first tube is serially diluted through the remaining tubes?
Signup and view all the answers
What would the concentration of antibody be in the final solution in mg/dL, in a serial dilution if 0.10 mL of a 50 mg/L antibody stock solution is mixed with 0.40 mL of diluent; and then 0.10 mL of this dilution is serially diluted through 5 more tubes each containing 0.1 mL diluent?
What would the concentration of antibody be in the final solution in mg/dL, in a serial dilution if 0.10 mL of a 50 mg/L antibody stock solution is mixed with 0.40 mL of diluent; and then 0.10 mL of this dilution is serially diluted through 5 more tubes each containing 0.1 mL diluent?
Signup and view all the answers
In a serial dilution, 1.9 mL of saline is placed in tube #1, 0.5 mL of saline is placed in tubes #2 to #7, 0.1 mL of serum is added to tube #1 and mixed, and 0.5 mL of solution from tube #1 is then serially diluted through tubes #2 to #7. What is the serum dilution in tube #4?
In a serial dilution, 1.9 mL of saline is placed in tube #1, 0.5 mL of saline is placed in tubes #2 to #7, 0.1 mL of serum is added to tube #1 and mixed, and 0.5 mL of solution from tube #1 is then serially diluted through tubes #2 to #7. What is the serum dilution in tube #4?
Signup and view all the answers
A serial dilution is set up where the first tube contains 4 mL of diluent, the second and successive tubes contain 3.5 mL of diluent, 1.0 mL of whole blood is added to tube #1 and mixed, and 0.5 mL of the dilution from tube #1 is serially diluted through tubes #2 to #5. What is the total dilution in tube #5?
A serial dilution is set up where the first tube contains 4 mL of diluent, the second and successive tubes contain 3.5 mL of diluent, 1.0 mL of whole blood is added to tube #1 and mixed, and 0.5 mL of the dilution from tube #1 is serially diluted through tubes #2 to #5. What is the total dilution in tube #5?
Signup and view all the answers
If the blood in the serial dilution from the previous question contained factor X at an original concentration of 4.096 x 10^-1 g/dL, what is the final concentration in g/dL?
If the blood in the serial dilution from the previous question contained factor X at an original concentration of 4.096 x 10^-1 g/dL, what is the final concentration in g/dL?
Signup and view all the answers
If the original serum glucose concentration is 20.0 mmol/L, what would the concentration be in tube #5 of a serial dilution with a dilution factor of 1/2, except for the first tube which has a dilution factor of 1/24?
If the original serum glucose concentration is 20.0 mmol/L, what would the concentration be in tube #5 of a serial dilution with a dilution factor of 1/2, except for the first tube which has a dilution factor of 1/24?
Signup and view all the answers
If the concentration of urea in tube #3 of a serial dilution was 0.050 mmol/L, what was the concentration of urea in the patient's undiluted sample, assuming the serial dilution factors are 1/2, except for the first tube which has a dilution factor of 1/24?
If the concentration of urea in tube #3 of a serial dilution was 0.050 mmol/L, what was the concentration of urea in the patient's undiluted sample, assuming the serial dilution factors are 1/2, except for the first tube which has a dilution factor of 1/24?
Signup and view all the answers
Study Notes
MEDL 210: Analytical Techniques
- Course: Medical Laboratory Technology
- Semester: Fall 2019
- Course component: Laboratory Math 1
Rationale
- Clinical laboratory mathematics, including concentration and dilution calculations, are frequently performed.
- These calculations are essential for preparing reagents, controls, standards, and interpreting patient results.
- All laboratory workers must have a good understanding of laboratory mathematics.
Learning Outcome
- Apply mathematical principles for preparing solutions and samples in medical laboratories.
Introduction
- Medical laboratories use various solutions and measurements.
- Solutions are composed of a solute (dispersed phase) and a solvent (dispersing phase).
- Concentration is a measure of the amount of solute relative to solvent.
- Several methods exist for expressing concentration, including calculations and manipulations.
- Single and serial dilutions are routinely performed in laboratories, and calculations involving these are discussed.
Note on rounding off numbers
- Measurements are often rounded to a specific decimal place.
- Rules for experimental data rounding:
- If the digit dropped is less than 5, leave the preceding digit unchanged.
- If the digit dropped is greater than 5, increase the preceding digit by 1.
- If the digit dropped is 5 and followed by no other digits, round up if the preceding digit is odd, otherwise round down.
- Clinical laboratory results often follow specific reference (normal) ranges.
Expressions of concentration in the medical laboratory
-
Molarity (M):
- Defined as the number of moles of solute per liter of solution.
- Formula: Molarity = (moles of solute) / (liters of solution).
- Example calculations involving concentration and dilutions like NaCl are demonstrated.
Osmolarity (Osm)
- Osmolarity is the number of osmoles of solute per liter of solution.
- Osmoles are calculated based on the ions or molecules formed upon dissociation of a solute molecule.
- Calculations for osmolarity involve converting molarity to osmolarity.
- Osmolarity problem calculation examples are included in the study notes.
Weight per Volume - % (W/V)
- Concentration is in grams solute per 100mL of solution.
- Example problems involving percent solutions are shown.
Percentage by Volume - % (V/V)
- Concentration is in mL of liquid solute per 100mL of solution.
- This is often used for liquid-in-liquid solutions.
- Example problems are provided.
Molality (m) and Osmolality (osm)
- Molality: Defined as the number of moles of solute per kilogram of solvent.
- Osmolality: Defined as the total osmoles of solute particles per kilogram of solvent
Molarity and pH
- pH calculation from molarity (concentration) of hydrogen ions (H+).
- pH is the negative log of H+ concentration.
- Calculating pOH for solutions of strong bases.
- Relationship between pH and pOH, which always sum to 14
Dilution of Reagents and Solutions
- Dilution is the process of creating a weaker solution from a concentrated one.
- Ratios are used to express the relative amounts of substances in solutions.
- When working with dilutions, it is important to clarify the comparison
- Examples of various ratio applications are shown.
- Common fractions are commonly used for dilution expressions.
- Single and serial dilutions are used in the clinical laboratory.
Exercise One and Two
- A series of questions and problems related to dilution and concentration calculations are presented.
- Worked out examples of calculations are provided in each problem.
Exercise Three
- Questions related to serial dilutions and calculations are presented.
- Important concepts for performing calculations in serial dilutions are described.
- Problems of varying complexities are included.
Exercise One and Two Answers
- These are step-by-step calculations in a problem-solving methodology which are in a Q&A format.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your understanding of laboratory mathematics used in medical laboratories. This quiz covers concentration and dilution calculations essential for preparing reagents and interpreting patient results. Ensure you grasp the mathematical principles applied in laboratory settings.
