90 Questions
What role can semipolar solvents, like ketones, play in solutions?
Inducing polarity in nonpolar solvent molecules
Which type of solutions are of pharmaceutical importance according to the text?
Liquids in liquids
What does Henry's law state about the relationship between the concentration of dissolved gas and the partial pressure?
The concentration is directly proportional to the partial pressure
How does the solubility of a gas in a liquid change with temperature?
Increases with higher temperature
What factor does the solubility of a gas in a liquid depend on according to the text?
Pressure, temperature, salts, and chemical reactions
What is the main purpose of semipolar solvents like acetone in solubility processes?
Enhancing miscibility between polar and nonpolar liquids
What happens to the solubility of gases as temperature increases?
Decreases
Why should a container of gaseous solution or high vapor pressure liquid be immersed in ice before opening in warm climates?
To reduce the temperature and pressure of the gas
What effect does adding electrolytes like NaCl to gaseous solutions have?
Increases liberation of gases
What defines an ideal solution according to Raoult's law?
Adhesive forces are equal to cohesive forces
What is a saturated solution?
A solution with dissolved solute in equilibrium with the solid phase
In real solutions, when do components not obey Raoult's law?
When they are of two types
How is solubility defined in quantitative terms?
As the concentration of solute in a saturated solution at a certain temperature
Why do electrolytes like NaCl induce liberation of gases from gaseous solutions?
Because the gas molecules are highly attracted to the electrolyte ions
What is an unsaturated solution?
A solution containing dissolved solute below saturation point at a definite temperature
What happens in a supersaturated solution?
More solute is present than it would normally contain at that temperature
In the example given, why does glucose precipitate from the solution when cooled?
Because the system has a higher amount of dissolved glucose than predicted by the solubility limit
What distinguishes a supersaturated solution from a saturated one?
More solute present than it would normally contain at a specific temperature
What is the guiding principle for selecting a suitable solvent?
Like dissolves like
Which type of solutes dissolve best in nonpolar solvents?
Nonpolar solutes
How does branching in the carbon chain of aliphatic alcohols affect water solubility?
It increases water solubility
What feature of polar solvents plays a role in reducing the force of attraction between oppositely charged ions in crystals?
Dielectric constant
Which type of compounds are generally water-soluble due to the presence of additional polar groups?
Polyhydroxy compounds
In which types of alcohols does the presence of straight chains with more than 5 carbon atoms lead to slight solubility in water?
Primary alcohols
What is the formula for the distribution coefficient (K) used to determine the efficiency of extracting a compound from a solvent?
K = Wn / (KV1 + V2)
According to the equation provided, when is an extraction most efficient?
When n is large and V2 is small
What is meant by 'weight in grams of a solute is extracted repeatedly' in the context of the provided equation?
The weight of the solute extracted multiple times
In the given example, what does K = 0.012 represent?
The distribution coefficient for iodine between water and carbon tetrachloride
What does 'CH2O/CCCl4' represent in the context of the given example?
The distribution coefficient between two solvents
What impact does increasing 'n', the number of extraction repetitions, generally have on extraction efficiency?
Increases efficiency
What does the equation for an ideal solution of a solid in a liquid indicate about solubility at temperatures above the melting point?
Solubility does not apply above the melting point
In an ideal solution, what state is the solute in when temperatures are above its melting point?
Liquid state
What happens to the solute's solubility as the temperature of the solution increases according to the provided example?
Solubility increases
What is the effect on solubility when the temperature of a solution is lowered?
Solubility decreases
What does the term 'miscible in all proportions' in the context of an ideal solution imply?
Solute mixes uniformly with solvent regardless of quantity
What is the significance of R=1.987 Cal/mole.k in determining solubility according to the provided equation?
It represents a constant in the solubility equation
Which indomethacin polymorph has the lowest melting point?
Polymorph VII
Based on the solubility ranking given in the text, which property is more useful in ordering the solubility of indomethacin polymorphs?
Molar heat of fusion (∆Hf)
What is the ideal mole fraction solubility of polymorph I at 25°C based on the provided data?
$0.0069$
In non-ideal solutions, what should be considered, according to the text?
Electrostatic and intermolecular forces
What factor determines the solubility ranking of the indomethacin polymorphs?
Molar heat of fusion
If polymorph II has a molar heat of fusion of 9700 cal/mole, what is its ideal mole fraction solubility?
$0.0073$
In the context of solubility expressions, what does the activity coefficient measure?
The deviation from ideal behavior in a solution
Which statement best describes the relationship between an ideal solution and its activity coefficient (ɣ2)?
As a real solution becomes more ideal, ɣ2 approaches unity.
What happens to the mole fraction solubility of a solute as the solution becomes more ideal?
Decreases as the activity coefficient approaches unity
How is the mole fraction solubility expressed in a non-ideal solution when converted to logarithmic form?
$log X2 = log \gamma_2 - log 2.303RTT_0$
What does the term 'solubility in an ideal solution' refer to in the provided text?
The solubility of a solute when the activity coefficient is equal to 1
What is the significance of the equation $log a_2 = -log \lambda = 2.303RTT_i$ in solubility calculations?
It demonstrates how ideal solutions differ from non-ideal solutions
What happens to the solubility of Na2SO4.10H2O as the temperature increases above 32°C?
It decreases
How does the solubility of sodium chloride change with a temperature increase?
It remains the same
What happens to weak acids when pH is lowered to below 9.3?
They precipitate from the solution
How do weak bases behave in the presence of stronger basic substances?
They precipitate as free bases
Which process is exothermic for Na2SO4 above 32°C?
Precipitation of Na2SO4
Why do alkaloidal salts like atropine sulfate begin to precipitate when the pH is elevated?
They precipitate as free bases
What is the special constant used to describe the solubility of slightly soluble electrolytes?
Solubility product (Ksp)
In the equilibrium expression [Ag+][Cl-] = Ksp, why are concentrations used instead of activities?
Solid phase concentration is essentially constant
What does raising the concentration of each ion to a power equal to the number of ions appearing in the formula indicate?
Equilibrium expression
In the given example, what does the measured solubility of silver chloride of 1.12 x 10^-5 mole/liter at 20°C represent?
Concentration of solute
How does the equilibrium expression for aluminum hydroxide, Al(OH)3, differ from that of silver chloride, AgCl?
[Al3+][OH-] = Ksp vs. [Ag+][Cl-] = Ksp
Why are concentrations used instead of activities in the equilibrium expressions for slightly soluble electrolytes?
To maintain constant ionic strength
In an ideal solution of solids, what factor does NOT affect the solubility of a solid?
Nature of the solvent
What is the term used to describe the increase in mutual solubility of two partially miscible solvents by another agent?
Blending
In a real (non-ideal) solution of solids, what is the relationship between the heat of solution and the heat of fusion?
Unrelated
If a material is soluble in both liquids in a liquid pair, how is the mutual solubility of the liquids affected?
Increased
What action on a phenol-water system leads to an increase in their mutual solubility?
Addition of succinic acid
What is meant by 'blending' when discussing the solubility of two partially miscible solvents?
Increasing the miscibility
What does the rational activity coefficient (ɣ2) represent in the formula a2 = X2ɣ2?
Correction factor for non-ideal behavior
In an ideal solution, what is the value of the activity coefficient (ɣ2)?
1
What does the equation 𝜟𝑯𝒇 𝑻𝟎 − 𝑻 𝒊 𝐥𝐨𝐠 a 𝟐 = −𝐥𝐨𝐠𝝌 = 𝟐 𝟐.𝟑𝟎𝟑𝑹 𝑻𝑻𝟎 imply about the solubility of a solute in a non-ideal solution?
Solubility decreases with increasing temperature
What happens to the mole fraction solubility of a solute as the solution becomes more ideal?
Approaches zero
How does the mole fraction solubility in various solvents change as the rational activity coefficient (ɣ2) approaches unity?
Remains constant
What is the significance of the ideal solubility equation a2=𝝌 in an ideal solution?
Demonstrates the concept of an ideal solution
What is the qualitative definition of solubility as provided in the text?
The interaction of substances to form a homogeneous dispersion
In the example given, why does glucose sometimes take a while to crystallize after cooling the solution?
It takes time for the molecules to find their solid structure positions
What is a supersaturated solution, according to the text?
A solution with more dissolved solute than normal at a certain temperature
What happens if a solution is cooled to 25°C and 9 g of glucose precipitates, but the system has 100 g of dissolved glucose?
The system is supersaturated with glucose
What phenomenon occurs when a solution contains less dissolved solute than needed for complete saturation at a specific temperature?
Unsaturated or subsaturated solution
If a solution contains only the necessary amount of solute to be in equilibrium with the solid phase at a given temperature, what type of solution is it?
Saturated solution
In the context of the provided text, what does the term 'C' represent in the equation C = (Kq+1 + Ka/[H3O+])[HA]w?
Total concentration of benzoic acid needed to preserve an oil-water mixture
What is the purpose of the dissociation constant Ka in the context of the mentioned equations?
To measure the concentration of undissociated acid in the aqueous phase
What does the volume ratio 'q' represent in the equation C = (Kq+1 + Ka/[H3O+])[HA]w?
Volume ratio of peanut oil to water
Based on the text, what does 'Ka' being 6.4 x 10^-5 indicate about the acid in water?
Weak acidic properties of the acid
How does the partition coefficient 'K' influence the distribution of benzoic acid between peanut oil and water?
Affects how much benzoic acid remains in the water phase
What role does the total concentration 'C' play in achieving a final specified concentration [HA]w of undissociated acid in the aqueous phase?
Calculates the amount needed to maintain undissociated acid at a specific pH
What happens to the solubility of a gas in a liquid when the pressure above the solution decreases, as explained in the text?
The gas escapes from the solution.
In the context of solubility and distribution, what does the term 'effervescent solutions' refer to?
Solutions that contain a gas under pressure
What phenomenon occurs when the stopper of a container with an effervescent solution is removed?
The gas escapes violently.
How does the temperature affect the solubility of a gas in a liquid, based on the information provided?
As temperature increases, gas solubility decreases.
What happens to the solubility of a gas in a liquid when the total pressure above the mixture is decreased?
The gas escapes from the solution.
Based on the given examples and information, what factor primarily determines the amount of a gas that can be dissolved in a liquid?
The partial pressure of the undissolved gas above the solution
Learn about semipolar solvents like ketones and their role in inducing polarity in non-polar solvent molecules. Explore how semipolar solvents can help enhance the miscibility of polar and non-polar liquids, with examples like acetone increasing solubility of ether in water. Also, discover the types of solutions important in pharmaceutical chemistry, such as gases in liquids, liquids in liquids, and solids in liquids covered in Chapter 10 of Solubility and Distribution.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
