1 / 20

Chapters 17/23

Chapters 17/23. Classification of Matter. Pure Substance. One substance and only one substance is in the material. A pure substance can be an element or a compound. Element. A substance found on the periodic table.

rsally
Télécharger la présentation

Chapters 17/23

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapters 17/23 Classification of Matter

  2. Pure Substance • One substance and only one substance is in the material. • A pure substance can be an element or a compound.

  3. Element • A substance found on the periodic table. • An element cannot be broken into a smaller substance and remain a substance.

  4. Compound • A pure substance that is a chemical combination of two or more elements.

  5. Compound • A compound has these characteristics: 1. They are hard to separate into their components. 2. They are chemically combined to form a new substance. 3. The components must be in proportion to each other.

  6. Compound • Sodium metal + chlorine gas yields sodium chloride (table salt)

  7. Mixtures • A physical combination of two or more pure substances. The substances remain what they were, but may change size, shape or state of matter

  8. Mixtures • A mixture has 3 characteristics: 1. It can be easily separated. 2. It is physically combined so all substances retain their original properties. 3. Combined substances are not in certain proportions: a little or a lot can be combined to form the same type of mixture.

  9. A mixture can be easily separated in three ways • Sifting: particles are “picked” apart • Evaporation: A liquid is heated to the gaseous state and move from container; solid(s) remain in container • Distillation: A liquid as it evaporates is collected another container and cooled to a liquid again, leaving impurities in original container

  10. Types of Mixtures • There are 2 types of mixtures: • Heterogeneous • Homogeneous

  11. Heterogeneous Mixture • A mixture where individual substances can easily be identified just by looking at the mixture. The particles of a heterogeneous mixtures are called a precipitate.

  12. Heterogeneous Mixtures 2 types • Colloid: Particles in the mixture stay suspended • Suspension: Particles in the mixture settle out to the bottom

  13. Homogeneous mixtures • A mixture that looks the same throughout.

  14. Homogeneous Mixtures • These mixtures can also be called solutions. • A solution consists of two parts: • Solute: the substance that is dissolved • Solvent: the substance that causes the dissolving

  15. Special Solutions • Air: a gaseous solution • Alloy: a solid solution of metals

  16. Solubility • Solubility is the rate at which a given amount of solute is dissolved in a given amount of solvent at a given temperature. • Solubility depends on 1. The temperature of the solvent and/or solute 2. The size of the solute particles 3. Whether or not the mixture is agitated.

  17. Classification of Solutions • Solutions can be • Diluted: much solvent; little solute • Concentrated: much solute; little solvent Solutions can also be classified as • Saturated: No more solute can be dissolved into solution • Unsaturated: more solute can be dissolved into solution • Supersaturated: more solute than normal has been dissolved into solution.

  18. Physical Changes • A physical change changes the appearance of the substance only. The substance remains what it was originally. • A physical change can be 1. a change in size 2. a change in shape 3. a change in state of matter

  19. Chemical Change • A chemical change in a substance results in a new substance being formed. The new substance will have completely difference properties from the material that was combined

  20. Chemical Change • A chemical change can be detected with the following signs: 1. There is a complete color change. 2. Gas is released upon the combination 3. A precipitate is formed when two clear liquids are combined 4. Energy is transformed: Exothermic: heat is given off Endothermic: heat is taken in

More Related