States of Matter and Phase Transitions in Anesthesia

Flashcards covering matter, phase transitions, kinetic molecular theory, intermolecular forces, solubility, and anesthetic vaporizers based on lecture.

What is the definition of a solution?

A homogeneous mixture that consists of one or more solutes dispersed in a solvent.

In a solution, which component is present in a larger amount?

The solvent.

In a solution, which component is present in a smaller amount?

The solute.

What are the two identifying characteristics that all matter possesses?

Mass and volume.

What are the three chemical properties used to identify matter according to the notes?

Flammability, reactivity, and toxicity/oxidation.

What are identifying physical properties of matter mentioned in the lecture?

Melting point, density, solubility, freezing point, and volume.

How are the properties of the three states of matter explained?

By looking at the arrangement of their particles.

What characterizes the volume and shape of a solid?

A solid has a definite volume and a definite shape.

How are molecules arranged in a solid?

They are closely packed together and held rigidly in place by strong intermolecular forces.

What allows ice to be less dense than liquid water?

Stable hydrogen bonds hold molecules apart, creating vacant space.

What characterizes the volume and shape of a liquid?

Liquids have a definite volume but no definite shape.

What allows liquids to have the ability to flow?

Intermolecular forces are strong enough to hold molecules in a condensed phase but not strong enough to prevent them from sliding past each other.

What characterizes the volume and shape of a gas?

Gases have neither a definite shape nor a definite volume.

What is the status of intermolecular forces in the gas phase?

They are essentially zero between gas molecules or very weak.

How do molecules in a gas move?

They fly in all directions at great speeds.

What is the plasma state of matter?

A mixture of electrons and nuclei that results when atoms lose their electrons at very high temperatures, such as in stars.

What are phase transitions?

Changes in the physical state of matter.

Which phase transitions are classified as endothermic processes?

Fusion (melting), vaporization, and sublimation.

What occurs during an endothermic process in terms of heat?

The system absorbs heat and cools the surroundings.

Which phase transitions are classified as exothermic processes?

Freezing (solidification), condensation, and deposition.

What occurs during an exothermic process in terms of heat?

The system releases heat and warms the surroundings.

What two factors cause substances to change their state of matter?

Temperature and pressure changes.

What is the enthalpy of reactants compared to products in an endothermic reaction?

The enthalpy of reactants is lower than that of products.

What is the enthalpy of reactants compared to products in an exothermic reaction?

The enthalpy of reactants is higher than that of products.

What is the mathematical sign of the change in enthalpy ($\Delta H$) for an endothermic reaction?

Positive ($\Delta H > 0$).

What is the mathematical sign of the change in enthalpy ($\Delta H$) for an exothermic reaction?

Negative ($\Delta H < 0$).

Define Heat of Fusion ($\Delta H_{fus}$).

The heat necessary to convert one mole of a solid into a liquid at its normal melting point.

What does $\Delta H_{fus}$ represent on a molecular level?

The energy needed to break down intermolecular forces to allow molecules to slide around in the liquid phase.

Why is melting ice in a glass of water an endothermic reaction?

The ice absorbs heat energy from the water, causing the water to become colder.

Define Heat of Vaporization ($\Delta H_{vap}$).

The heat required to convert one mole of liquid to a gas at a constant temperature.

What does $\Delta H_{vap}$ represent on a molecular level?

The energy needed to break or overcome intermolecular forces so molecules can escape the liquid into the gas phase.

What are the three steps in the enthalpy of solution process?

1. Breaking bonds in the solute. 2. Breaking bonds in the solvent. 3. Forming new bonds between solute and solvent.

Is the process of breaking bonds during dissolution endothermic or exothermic?

Endothermic (requires energy).

Is the process of forming new bonds between solute and solvent endothermic or exothermic?

Exothermic (releases energy).

What does a positive enthalpy of solution indicate?

An endothermic reaction.

What does a negative enthalpy of solution indicate?

An exothermic reaction.

Define 'latent heat of vaporization' according to the quiz question on page 22.

The number of calories required to convert one gram of liquid to vapor without a temperature change in the liquid.

How is the risk of ionizing radiation exposure related to the distance from the source?

It is inversely proportional to the square of the distance of the source.

What factors affect the enthalpy of solution?

Temperature, pressure, and the nature of the solute and solvent.

What is a phase diagram?

A graphical representation showing the physical states of a substance under different conditions of temperature and pressure.

What does the Triple Point on a phase diagram represent?

The conditions of temperature and pressure where all three states of matter coexist in equilibrium.

Define the Critical Point.

The conditions of temperature and pressure under which a liquid and vapor can coexist; it is the endpoint of the phase equilibrium curve.

What is critical temperature ($T_c$)?

The highest temperature at which a gas can exist as a liquid, or the temperature above which a gas cannot be liquefied regardless of pressure.

What is critical pressure ($P_c$)?

The minimum pressure required to convert a gas to a liquid at its critical temperature.

Why do Nitrous Oxide and Carbon Dioxide exist as liquids inside their cylinders at room temperature?

Their critical temperatures ($36.5^\circ C$ and $31^\circ C$) are higher than room temperature ($\approx 20^\circ C$).

Why do Oxygen, Air, and Nitrogen exist as gases inside their cylinders at room temperature?

Their critical temperatures are less than room temperature (e.g., Oxygen is $-119^\circ C$).

What is the critical temperature of Nitrous Oxide?

$$36.5^\circ C$$

What is the critical temperature of Carbon Dioxide?

$$31^\circ C$$

What is the critical temperature of Oxygen?

$$-119^\circ C$$

What is the critical temperature of Nitrogen?

$$-147^\circ C$$

What is the critical pressure of Oxygen?

$$50\,bar$$

What is the critical pressure of Nitrous Oxide?

$$72\,bar$$

What is the critical pressure of Carbon Dioxide?

$$73\,bar$$

According to KMT, matter is made up of what?

Small particles (atoms or molecules) that are in constant random motion.

What does KMT say about the volume of individual gas particles?

It is assumed to be negligible (zero) compared to the distance between particles.

According to KMT, what causes the pressure exerted by a gas?

Collisions of particles with the walls of the container.

What is the KMT assumption regarding attractive or repulsive forces between gas particles?

The particles are assumed not to attract or repel each other (IMF is negligible).

How is the average kinetic energy of gas particles related to temperature in KMT?

It is directly proportional to the Kelvin temperature ($T$).

What happens to the kinetic energy of particles if the temperature of a substance increases?

The kinetic energy increases and the particles move faster.

What is an elastic collision in the context of KMT?

A collision where there is no net loss or gain of kinetic energy.

How do Real Gases differ from Ideal Gases regarding intermolecular forces?

Real Gases have attractive forces between particles that become stronger as they move closer together.

What are Van der Waals or London forces?

Weak intermolecular attractions between separate gas particles.

At what conditions do Real Gases deviate most from Ideal Gas behavior?

High pressures and/or low temperatures.

In the Van der Waal's equation, what does the constant 'a' correct for?

Intermolecular attractions between gas molecules.

In the Van der Waal's equation, what does the constant 'b' correct for?

The finite volume of the gas molecules.

Define 'ideal bond length'.

The distance between two positively charged nuclei where the energy is at a minimum and the molecule is at maximum stability.

What is 'bond dissociation energy' (BDE)?

The amount of energy necessary to break a chemical bond; it measures the strength of the bond.

Contrast Intramolecular and Intermolecular forces.

Intramolecular forces act within a molecule (bonds), while intermolecular forces act between different molecules.

Which are generally stronger: Intramolecular or Intermolecular forces?

Intramolecular forces.

What are the two main types of intramolecular chemical bonds?

Ionic bonds and Covalent bonds.

Define an Ionic bond.

A chemical bond formed through the electrostatic attraction between oppositely charged ions, usually involving a transfer of electrons from a metal to a non-metal.

What is the 'Octet Rule' in covalent bonding?

Atoms tend to share electrons to achieve a noble gas-like configuration with 8 valence electrons.

What is a Polar Covalent Bond?

A bond between two non-metals with different electronegativities, resulting in unequal sharing of the bonding electron pair.

What is 'electronegativity'?

The tendency of an atom in a molecule to attract electrons to itself.

Which element is the most electronegative on the periodic table?

Fluorine ($EN = 4.0$).

What physical property is characteristic of a 'polar' molecule?

It exhibits electrical poles or dipoles (a positive end and a negative end).

Give two examples of polar molecules common in biological systems.

Water ($H_{2}O$) and Ammonia ($NH_{3}$).

What defines a Nonpolar Covalent Bond?

A bond where electrons are shared equally because the atoms have identical or very similar electronegativities.

Give four examples of nonpolar gases.

Hydrogen ($H_{2}$), Nitrogen ($N_{2}$), Oxygen ($O_{2}$), and Carbon Dioxide ($CO_{2}$).

What does VSEPR theory stand for and what is its purpose?

Valence Shell Electron Pair Repulsion theory; used to predict the 3-D shape of individual molecules.

What are the four main varieties of Intermolecular Forces (IMF)?

Ion-dipole, Hydrogen bonding, Dipole-dipole, and London forces.

What are London Dispersion Forces?

Attractive forces created by instantaneous dipoles present in all molecules and atoms.

What is the requirement for London Dispersion Forces to exist?

An electron cloud.

Among the IMF types, which is generally the strongest?

Ion-dipole forces.

What is Hydrogen bonding?

An attraction between a hydrogen atom bonded to a highly electronegative atom (F, O, or N) and another electronegative atom.

How do intermolecular forces impact boiling and melting points?

Stronger IMF result in higher melting and boiling points.

What is the relationship between IMF and vapor pressure?

Stronger IMF result in lower vapor pressure (inverse relationship).

Define Colligative Properties.

Physical changes that result from adding solute to a solvent; they depend on the number of solute particles, not their identity.

List the four colligative properties mentioned in the lecture.

Vapor pressure decrease, boiling point increase, freezing point decrease, and osmotic pressure increase.

What factors determine a substance's physical properties?

Type of IMF, molecular size, degree of branching/shape, and the number of hydrogen bond sites.

How does surface area (branching) affect IMF?

Linear molecules have more contact surface area and thus stronger IMF/higher boiling points compared to spherical branched molecules.

What is the definition of Boiling Point?

The temperature at which the vapor pressure of a liquid equals the ambient (atmospheric) pressure.

How does increased altitude affect the boiling point of water?

The boiling point decreases because the atmospheric pressure is lower.

At what temperature does water boil at sea level?

$100^\circ C$ ($212^\circ F$).

What is 'viscosity'?

A measure of a fluid’s resistance to flow.

What is Poiseuille’s Law formula for flow ($Q$)?

$$Q = \frac{\Delta P \pi r^{4}}{8 \eta L}$$

Under what condition does Poiseuille’s Law apply?

When fluid flow is laminar only.

In Reynolds' number ($Re$), what value indicates laminar flow?

$$Re < 2000$$

In Reynolds' number ($Re$), what value indicates turbulent flow?

$$Re > 4000$$

At low flow rates in a flowmeter, what property of the gas is flow dependent on?

Viscosity (due to laminar flow).