Liquids

The course starts with the discussion about the general properties of liquids. The course then compares the properties of gases, solids and liquids. It then goes on to explain the different types of intermolecular forces of attraction like dispersion forces, dipole dipole bonding, hydrogen bonding, ion dipole interactions that exist in liquids in detail along with the comparison of intermolecular forces. The course then proceeds to define viscosity and discuss the different factors on which viscosity of a liquid depends on. Stokes' law is also explained with reference to viscosity along with it’s different mathematical equations. As the course advances, the liquid-vapor interface is discussed in detail which includes discussion on surface tension, curved surfaces, and capillary action. The course also discusses phase changes and phase diagrams along with vapor pressure. The course concludes with the discussion on liquid crystals.

10 topics

215 lectures

Educators

UO

Course Curriculum

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16 videos

16 videos

27 videos

Chemical Equilibrium

34 videos

Acids and Bases

37 videos

Aqueous Equilibria

18 videos

18 videos

Electrochemistry

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Nuclear Chemistry

13 videos

Liquids Lectures

Liquids

Liquids - Intro

A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, a liquid is one of the four fundamental states of matter (the others being solid, gas and plasma). A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, leading to wetting phenomena.

Kim Pham

Liquids

Comparison Of Gases Liquids And Solids

A liquid is a state of matter in which a substance changes its shape easily and takes the form of its container, and in which the substance retains a constant volume independent of pressure. As a result of this, a liquid does not maintain a definite shape, and its volume is variable. The characteristic properties of a liquid are surface tension, viscosity, and capillarity. The liquid state has a definite volume, but it also has a definite surface. The volume is uniform throughout the whole of the liquid. Solids have a fixed shape and a definite volume, but they do not have a definite surface. The volume of a solid does not vary, but the volume of a liquid may vary.

Kim Pham

Liquids

Dispersion Forces

In physics, dispersion (also known as anomalous dispersion or optical activity) is the phenomenon in which the refractive index of a material depends on the frequency (and wavelength) of light, a phenomenon that causes the separation of a light beam into a visible "spectrum" of colors. The phenomenon is commonly observed in liquids and glasses.

Kim Pham

Liquids

Dipole - Dipole Bonding

A dipole is a separation of positive and negative charges within a molecule. The simplest example of this is the electric dipole, which occurs in molecules such as water, in which a separation of positive and negative charges occurs due to the asymmetrical arrangement of the two hydrogen atoms and the oxygen atom.

Kim Pham

Liquids

Hydrogen Bonding

Hydrogen bonding is a chemical phenomenon in which a hydrogen atom is covalently bonded to another atom by an electrostatic attractive force, which is stronger than a typical covalent bond. The force is also of an intermolecular nature, meaning that it occurs between molecules.

Kim Pham

Liquids

Ion Dipole Interactions

Ion–dipole interactions are electrostatic interactions between ions and polar molecules such as water. The resulting attraction or repulsion is usually very weak, but can be significant in aqueous solutions.

Kim Pham

Liquids

Comparison Of Intermolecular Forces

In physics, intermolecular forces are the forces which exist between the molecules of a substance. They are the forces which hold a molecule together and determine many of its physical properties. The study of intermolecular forces starts from macroscopic observations which indicate the existence and strength of these forces.

Kim Pham

Liquids

Viscosity

Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. For liquids, it corresponds to the informal concept of "thickness": for example, honey has a higher viscosity than water. Viscosity is a tensor property, and is measured by the ratio of the shear stress to the velocity gradient in a fluid. Viscosity is a property of the fluid which is being deformed, and not of the deforming particles themselves. Viscosity is a measure of the internal resistance of the fluid which is being deformed by either shear or tensile stress. The SI unit for viscosity is the pascal second.

Kim Pham

Liquids

Surface Tension

Surface tension is the elastic tendency of a surface to minimize its area. Surface tension allows insects to walk on water and causes the shape of soap bubbles. Surface tension is an important factor in the design of microfabricated devices.

Kim Pham

Liquids

Capillary Action

In physics, capillary action or capillarity refers to the tendency of a fluid to rise in a thin tube against the force of gravity. The effect is named after the Latin word for "hair", "capillum", a word used by the Roman architect Vitruvius in the first century B.C. to describe the fine pores in a mortar.

Kim Pham

Liquids

Phase Changes

In physics, a phase is a region of space, throughout which all physical properties of a material are essentially uniform. Examples of physical properties include density, index of refraction, magnetization, and chemical composition. A simple description is that a phase is a region of material that is chemically uniform, physically distinct, and (to a good approximation) mechanically separable. In a system consisting of ice and water in a glass jar, the glass of the jar is a boundary between two phases. The ice is said to be in the "ice phase" and the water is said to be in the "water phase". The glass of the jar is called the "interface" between the two phases. The term "phase" is sometimes used as a synonym for state of matter, but there can be several immiscible phases of the same state of matter. Also, the term "phase" is sometimes used to refer to a set of equilibrium states demarcated in terms of state variables such as pressure and temperature by a phase boundary on a phase diagram.

Kim Pham

Liquids

Vapor Pressure

Vapor pressure is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. The equilibrium constant for the vapor pressure can be seen as a partial pressure of the vapor, if the system is also at equilibrium with its own liquid or solid. The pressure exerted by a vapor is known as vapor pressure. In a mixture of vapor and condensed phases, the vapor pressure of the individual components are added. This total vapor pressure is the sum of the partial pressures of each of the components in the mixture. The total vapor pressure is an equilibrium property and is independent of the total volume of the system.

Kim Pham

Liquids

Phase Diagrams

In thermodynamics, a phase diagram is a graph that shows the relationship between the state of a thermodynamic system and various other parameters such as its pressure and temperature. The state of the system is generally represented by a single point within the phase diagram. A phase diagram contains state lines, which are curves connecting points of the same state. For example, a single phase (e.g. water) will have a single curve on the diagram showing all the possible pressure and temperature combinations. The line will be labelled with the name of the single phase (e.g. "Water") and the points on the line will be the points on the phase diagram.

Kim Pham

Liquids

Liquid Crystals

Liquid crystals (LCs) are a state of matter that has properties between those of conventional liquids and those of solid crystals. For instance, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like manner. There are many different types of liquid crystals, with many different properties.

Kim Pham

Liquids

Liquids - Example 1

A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, a liquid is one of the four fundamental states of matter (the others being solid, gas and plasma). A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, leading to wetting phenomena.

Kim Pham

Liquids

Liquids - Example 2

A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, a liquid is one of the four fundamental states of matter (the others being solid, gas and plasma). A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, leading to wetting phenomena.

Kim Pham

Liquids

Liquids - Example 3

A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, a liquid is one of the four fundamental states of matter (the others being solid, gas and plasma). A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, leading to wetting phenomena.

Kim Pham

Liquids

Liquids - Example 4

A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, a liquid is one of the four fundamental states of matter (the others being solid, gas and plasma). A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, leading to wetting phenomena.

Kim Pham