States of Matter and Gas Laws

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Questions and Answers

What defines a crystalline solid?

Molecules are in a gas state at high temperature.

Molecules are packed in a regular, repeating pattern. (correct)

Molecules are arranged randomly without any order.

Molecules are only loosely held together.

What does Boyle’s Gas Law describe?

Pressure remains constant regardless of volume.

Pressure is directly proportional to volume.

Volume is directly proportional to temperature.

Pressure is inversely proportional to volume. (correct)

Why are polymorphs important in pharmaceuticals?

They have no impact on drug properties.

They determine the color of the drug.

They influence the drug's pH level.

They can alter the drug's solubility and bioavailability. (correct)

What is the definition of a pharmaceutical salt?

A crystalline substance formed by acid-base reactions. Signup and view all the answers

What is the relationship between particle size and dissolution rate?

Smaller particles dissolve faster than larger particles. Signup and view all the answers

What issue is associated with the anhydrous form of chloramphenicol palmitate?

It is not bioavailable. Signup and view all the answers

What is the angle of repose related to in pharmaceutics?

Flow properties of powders. Signup and view all the answers

What is defined as the heat required to convert a solid into a liquid?

Heat of fusion Signup and view all the answers

Which of the following is NOT an example of micromeritics properties?

Thermal conductivity Signup and view all the answers

What happens to kinetic energy as temperature increases?

Kinetic energy increases. Signup and view all the answers

What is the USP classification of particle size for 'very coarse' particles?

Particles pass through a #8 sieve (2,360 µm) Signup and view all the answers

What microscopy technique is primarily used for analyzing nanoparticles?

Transmission Electron Microscopy (TEM) Signup and view all the answers

How is porosity expressed in powders?

As a percentage of void space to bulk volume Signup and view all the answers

What does the term 'bulkiness' refer to in the context of powders?

The reciprocal of the apparent density, expressed in mL/g Signup and view all the answers

What is the key difference between true density and bulk density?

True density refers to the density of the particles, whereas bulk density includes voids between particles Signup and view all the answers

What does wettability measure with respect to a powder surface?

The interaction of the liquid with the powder surface Signup and view all the answers

What does 'true volume' of a powder refer to?

The volume of the powder particles themselves, excluding voids Signup and view all the answers

What is the angle of repose formula used to calculate?

tan θ = h / r Signup and view all the answers

How does smaller particle size influence powder flow?

Smaller particles tend to have worse flow properties Signup and view all the answers

What is a potential solution for wetting problems in pharmaceutical formulations?

Including surfactants in the formulation Signup and view all the answers

Study Notes

States of Matter

Solids, liquids, and gases are the three states of matter.
Kinetic energy increases with temperature (KE ∝ T).
Single covalent bonds typically have an energy of ~330 kJ/mol.

Boyle’s Gas Law

Boyle’s gas law states that pressure is inversely proportional to volume (PV = constant) at a constant temperature.

Pharmaceutical Aerosols

Pharmaceutical aerosols utilize phase transitions between gas and liquid.
They contain a liquefied gas as a dispersion medium or propellant.

Crystalline Solids

Crystalline solids have molecules arranged in a regularly ordered, repeating pattern.
Different crystalline forms of the same substance are called polymorphs.
Polymorphs can affect a drug's solubility, dissolution rate, bioavailability, and stability.

Amorphous Solids

Amorphous solids lack a regular arrangement of molecules.

Pharmaceutical Salts

Pharmaceutical salts are crystalline salts formed by combining an acidic or basic drug with a counterion.
They are used for improved bioavailability, developability, purification, and patent advantages.

Cocrystals

Cocrystals are crystalline complexes of two or more neutral molecules that are solid at ambient conditions.

Heat of Fusion

The heat required to convert a solid into a liquid by increasing intermolecular distances is called the heat of fusion.

Powder Properties

A powder is a dry substance composed of finely divided particles.
The science of small particles is called micromeritics.
Micromeritic properties include:
- Particle size
- Size distribution
- Shape
- Angle of repose
- Porosity
- Bulk density

Particle Size

Particle size affects pharmaceutical formulations by influencing:
- Mixing
- Blending
- Dose uniformity
- Powder flow
- Dissolution
- Suspendability
Smaller particles dissolve faster than larger particles.
Particle size can be measured using ensemble methods (e.g., sieving, light scattering) and number counting methods (e.g., microscopy).

USP Classification

The USP classifies particle size for "very coarse" particles as those that pass through a #8 sieve (2,360 µm).

Microscopy Techniques

Transmission Electron Microscopy (TEM) is used for analyzing nanoparticles.

Porosity

Porosity is the ratio of void space to the bulk volume, expressed as a percentage.

Bulkiness

Bulkiness is the reciprocal of the apparent density, expressed in mL/g.
Bulkiness is measured by the volume of the powder divided by the weight.

Density

True density refers to the density of the particles themselves, while bulk density includes the voids between particles.

Porosity Formula

The formula for porosity is: Porosity = (V_bulk – V_true) / V_bulk × 100.

Wettability

Contact angle is a measure of a powder surface's wettability by a liquid.
Young’s equation relates surface free energy to the contact angle of a liquid on a solid.
Wettability is important for ensuring the proper dispersion of powders in liquids and penetration of liquid into tablets.
Surfactants can be added to formulations to address wetting problems.

Volumes

True volume refers to the volume occupied by the powder particles themselves, excluding voids.
Bulk volume is the total volume occupied by a powder, including the void spaces.

Void in Micromeritics

Void is the ratio of the space (void) to the volume of the powder.

Equivalent Sphere Diameter

The equivalent sphere diameter is used to describe the size of irregular particles based on volume, surface area, or mass.

Powder Flow

Smaller particles tend to have worse flow properties.

Angle of Repose Formula

The angle of repose formula is: tan θ = h / r, where h is the height of the powder cone and r is the radius.

Particle Size and Aerosolization

Smaller particles are more effective for dry powder inhalers.

Magnesium Carbonate

True volume of magnesium carbonate powder measures the actual space occupied by the particles, calculated using true density and mass.
Bulk density of magnesium carbonate powder is the weight of the sample divided by the bulk volume.
Bulkiness is calculated by the bulk volume divided by the weight of the sample.

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Description

Explore the fundamental concepts of states of matter, including solids, liquids, and gases. This quiz covers important laws, such as Boyle’s gas law, and delves into the characteristics of crystalline and amorphous solids, as well as pharmaceutical applications. Test your knowledge on how these principles apply to real-world situations.