Chapter 7 Multiple Choice Questions

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. What is the name of the phase transition that occurs when a solid is converted directly into a gas (without going through the liquid phase)?

Melting correct incorrect

Boiling correct incorrect

Condensing correct incorrect

Sublimation correct incorrect

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. Which if the following statements are true about the Eutectic point on a two component (compounds A and B) phase diagram?

Both compounds are solid correct incorrect

The melting point of the mixture is lower than the melting points of either of the individual compounds correct incorrect

One compound is in the liquid phase whilst the other is in the solid phase correct incorrect

It always occurs when the ratio of compound A to compound B is 50:50 correct incorrect

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. On a phase diagram an isotherm indicates which of the following?

A region where the composition of the system is constant correct incorrect

A region where the pressure is constant correct incorrect

An area below which only the solid phase exists correct incorrect

A region where the temperature is constant correct incorrect

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. Which of the following statements is NOT true in relation to a system that has reached the critical temperature?

The system must a closed system correct incorrect

The system can be described as a homogenous fluid correct incorrect

Substances can have more than one critical temperature. correct incorrect

A surface between the liquid and vapour phases is no longer present. correct incorrect

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. On a two component solid-liquid phase diagram, an isopleth indicates which of the following?

A region where the pressure is constant correct incorrect

An area below which only the solid phase exists correct incorrect

An area above which only the liquid phase exists correct incorrect

A region where the composition of the system is constant correct incorrect

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. On a two component solid-liquid phase diagram, a tie line indicates which of the following?

A region where the temperature is constant correct incorrect

A region where the composition is constant correct incorrect

An area below which only the solid phase exists correct incorrect

An area above which only the liquid phase exists correct incorrect

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. Which of the following statements about the rate of dissolution of a solid API into an aqueous biological environment is true?

Increasing the particle size, decreases the dissolution rate resulting in a quicker onset of action correct incorrect

Increasing the particle size, increases the dissolution rate resulting in a quicker onset of action correct incorrect

Increasing the particle size, increases the dissolution rate resulting in a slower onset of action correct incorrect

Increasing the particle size, decreases the dissolution rate resulting in a slower onset of action correct incorrect

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. Which of the following statements is NOT true about cyclodextrins?

They are polysaccharides correct incorrect

They are useful for formulating hydrophobic APIs correct incorrect

They have a hydrophilic outer surface correct incorrect

They are useful for formulating hydrophilic APIs correct incorrect

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. Which of the following statements is NOT true in relation to the triple point on a single component phase diagram?

The point at which the solid, liquid and gaseous phases for a substance co-exist correct incorrect

The triple point exists for a substance occurs at a specific temperature and pressure correct incorrect

The triple point exists at a single temperature and is independent of pressure correct incorrect

The system must be enclosed so that no vapour can escape correct incorrect

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. The upper critical solution temperature is defined as:

The maximum temperature at which two components will remain immiscible as two distinct liquids correct incorrect

The minimum temperature at which two components will remain immiscible as two distinct liquids correct incorrect

The maximum temperature at which two components remain miscible correct incorrect

The minimum temperature at which two components remain miscible correct incorrect