Properties of Liquids

Mix and Flow of Matter

• Fluids are materials that can flow, such as water, air, blood, and materials that can be melted or dissolved in fluids.
• Fluids are essential for daily life, and their ability to flow allows them to perform work, such as moving mechanical parts in machinery.

Properties of Fluids

• The properties of fluids can be explained by looking at the tiny particles that make up the material.
• The particle model of matter involves key ideas, including:
• All substances are made of tiny particles.
• All particles in a pure substance are the same.
• The particles have spaces between them.
• The particles are always in motion, vibrating, rotating, and moving from place to place.
• The particles are attracted to each other, with the strength of the attractive force depending on the type of particle.

Solids

• Solids are made up of particles that are tightly packed together, with particles that are so close they cannot move around freely.
• Solids are greatly affected by gravity and can be ground into small pieces that can slip past each other when poured out of their containers.

Liquids

• Liquids are made up of particles that have enough energy to pull away from each other, with particles that slide around each other and vibrate close together in small clusters.
• Liquids take the shape of their container and flow to the lowest possible level.
• Liquids are affected by gravity and form a level surface when at rest.

Gases

• Gases are made up of particles that are far apart from each other, with an enormous amount of empty space between them.
• Gas particles flow past each other easily, move in every direction, and move extremely far apart.
• Gases take on the shape of their container and occupy all the space that they can fill.
• Unlike liquids, gases do not flow to the lowest possible level and can move against gravity.

Changes of State

• A change of state occurs when a substance is heated or cooled, causing the physical state of the substance to be transformed into another state.
• Examples of changes of state include melting (solid to liquid), vaporization (liquid to gas), and the reverse changes of state that occur when a substance is cooled.

Plasma

• Plasma is a gas-like mixture of positively and negatively charged particles that can conduct electricity.
• Plasma is the most common form of matter in the universe and exists naturally in stars and lightning.
• scientists consider plasma to be a fourth state of matter.### Changes of State
• Condensation: change from gas to liquid (e.g., water vapor in the air becoming liquid water)
• Freezing: change from liquid to solid (e.g., water becoming ice)
• Sublimation: change from solid to gas or gas to solid without becoming a liquid first (e.g., dry ice sublimating into carbon dioxide gas)

Morphing

• Morphing: a special effect in movies where characters change shape or form
• Example: dry ice (frozen carbon dioxide) sublimating into a gas, creating a "morphing" effect

Properties of Matter

• Pure Substances: contain only one type of particle (e.g., iron, gold, oxygen, sulfur, carbon)
• Mixtures: contain two or more pure substances (e.g., paint, orange juice, milk)
• Homogeneous Mixtures: mixtures with uniform properties (e.g., solutions, vinegar, clear air)
• Heterogeneous Mixtures: mixtures with non-uniform properties (e.g., rocks, Italian salad dressing, clay mixed with water)

Classification of Matter

• Elements: pure substances made up of one type of particle (e.g., iron, gold, oxygen)
• Compounds: pure substances made up of two or more elements (e.g., water, salt, sugar)
• Homogeneous Mixtures: solutions (e.g., sugar and water), suspensions (e.g., Italian salad dressing), and colloids (e.g., fog)
• Heterogeneous Mixtures: mechanical mixtures (e.g., rocks, soil, blood)

Dissolving

• Dissolving: the process of forming a homogeneous mixture by mixing two or more materials

• Particle Model: explains why materials dissolve, considering particle attractions and motion

• Factors Affecting Dissolving: particle attractions, particle motion, and the strength of attractions between particles### Mixtures and Solutions

• A mixture is a blend of two or more substances, where each substance maintains its chemical properties.

• A solution is a homogeneous mixture of two or more substances, where one substance (the solute) is dissolved in another substance (the solvent).

Solutes and Solvents

• Solute: the substance that dissolves in a solvent to form a solution.
• Solvent: the substance that dissolves a solute to form a solution.
• Example: sugar (solute) dissolves in water (solvent) to form a solution.

Examples of Solutions

• Air: oxygen, nitrogen, and other gases mixed together.
• Soda water: carbon dioxide (gas) dissolved in water.
• Vinegar: acetic acid (liquid) dissolved in water.
• Ocean water: various salts (solids) dissolved in water.

Water - the Universal Solvent

• Water is called the "universal solvent" because it can dissolve many materials.
• 97% of the water on Earth is ocean water, which contains many dissolved substances.
• Only 0.5% of the Earth's water is usable freshwater, but it also contains many solutes.

Dissolving

• The rate of dissolving can be affected by factors such as agitation (stirring or shaking), surface area, temperature, and pressure.
• Agitation helps to increase the rate of dissolving by pushing water particles closer to the solute particles.

Solubility

• Solubility refers to the maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature.
• A saturated solution is one in which no more solute can dissolve in the solvent at a specific temperature.
• An unsaturated solution is one in which more solute can dissolve in the solvent at the same temperature.
• Examples of solubility: salt (35.7 g/100 g of water), sugar (179.2 g/100 g of water), and copper(II) sulfate (31.6 g/100 g of water).

Supersaturated Solutions

• A supersaturated solution is one that contains more solute than it can normally hold at a specific temperature.
• Supersaturated solutions can be prepared by making a saturated solution and then cooling it without stirring.
• When a small crystal of solute is added to a supersaturated solution, the excess solute quickly crystallizes out of the solution.