30 Questions
What effect does the conversion of a weak acid to its sodium salt have on aqueous solubility?
Increases the aqueous solubility
Why is chloramphenicol palmitate used in pediatric suspensions instead of chloramphenicol base?
To mask the bitter taste of the drug
Which factor plays a role in increasing the ease of absorption of drugs from the gastrointestinal tract?
Using water-miscible cosolvents
What effect does esterification have on the solubility of a parent drug?
Decreases the solubility
Why are cosolvents like ethanol or propylene glycol used in drug formulations?
To act as better solvents for the drug
How does polymorphism relate to solvation in drug formulations?
No relationship between polymorphism and solvation
What does Henry's Law state?
The solubility of a gas is increased as the pressure of the gas increases.
What does Henry's Law constant, k, represent?
A constant specific to the gas-solvent pair.
Why does more gas dissolve into the liquid at pressure P2?
Because the pressure above the solution is higher.
What happens to the solubility of CO2 in soft drinks when the bottle is opened?
It decreases.
How does temperature affect the solubility of most gases?
Decreases solubility.
Why must pharmacists be careful in opening containers of gaseous solutions in warm climates?
To avoid rapid gas expansion and potential spills.
What is the classification of a solution based on the states in which the solute and solvent occur?
Liquid in solid
According to Henry’s Law, what is the relationship between the concentration of dissolved gas and the partial pressure of the gas above the solution?
They are directly proportional
What does vapor pressure represent in a closed system?
Pressure of a vapor in equilibrium with its condensed phases
In which type of solution does a gas occur both as a solute and solvent?
Gas in solid
How is the partial pressure of a gas calculated in Henry’s Law?
Subtracting the total pressure from the vapor pressure
What factor does NOT affect the solubility of gases in liquids?
Molarity of the solution
What is the purpose of immersing a vessel containing a gaseous solution in ice or cold water before opening it?
To reduce the temperature and pressure of the gas
What is the phenomenon known as when gases are liberated from solutions by the introduction of an electrolyte or non-electrolyte?
Salting-out effect
Which gases show deviations from Henry's law due to chemical reaction with the solvent?
Hydrogen chloride, ammonia, and CO2
What effect does salting-out have on the solubility of gases in solution?
Decreases solubility
In which type of systems are the components miscible in all proportions?
Ideal solutions
How does the presence of an electrolyte or non-electrolyte lead to the salting-out effect?
By reducing the density of the aqueous environment near gas molecules
What is the phenomenon called when organic solutes are taken up by the aggregates of solubilizing agents?
Micelle formation
In which type of solvents can a similar phenomenon to solubilization occur when polar solutes are taken up by more polar regions in the solution?
Organic solvents with dissolved solubilizing agents
What is the process where the apparent solubility of a solute in a liquid is altered by the addition of a third substance that forms an intermolecular complex with the solute?
Complex formation
Which of the following is NOT a result of complex formation between a third substance and a solute?
Transformation of the solvent
What preparation example involves complex formation for aiding in the solubility of mercuric iodide?
Preparation of mercuric iodide solution
If the center of aggregates in organic solvents with dissolved solubilizing agents is more polar than the bulk solvent, what happens to the apparent solubilities of polar solutes in these regions?
Increase in apparent solubilities
Study Notes
- Solubilizing agents form large aggregates or micelles in solution, increasing solubility of organic solutes in water or organic solvents.
- Complex formation with a third substance can increase or decrease the apparent solubility of a solute in a liquid.
- Henry's Law states that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas.
- Increased pressure increases the solubility of gases in liquids, while increased temperature decreases it.
- Gases can be liberated from solutions by salting out with electrolytes like NaCl or non-electrolytes like sucrose.
- Chemical reactions between gases and solvents may increase solubility, deviating from Henry's Law.
- The solubility of liquids in liquids depends on factors like miscibility, cosolvents, and crystal characteristics like polymorphism and solvation.
Test your knowledge on the classification of solutions based on the states of solute and solvent, including solid, liquid, and gas. Explore the nine possible types of homogeneous mixtures and understand the variations in pharmaceutical solutions.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
