Substances, Compounds & Mixtures

1. Substances, Compounds & Mixtures How everything is put together.

2. Classification of Matter

3. Elements • Matter that has the same composition and properties throughout is called an_____________. • When different elements combine, other substances are formed.

4. Elements • Contains only one particle • Can exist in 3 states of matter __________________________________ Picture from http://www.ilpi.com/msds/ref/gifs/statesofmatter.gif

5. Compounds • Ban DHMO? • DHMO is dihydrogen monoxide. • Evaluate the following link and decide if this potentially dangerous chemical should be prohibited. • www.dhmo.org

6. Compounds • A compound is a substance whose smallest unit is made up of atoms of more than one element _______________ together. • Compounds often have properties that are ___________ from the elements that make them up. • Examples:______________________________________

7. Compounds General Rules: - Only write the name of the metallic element _______________ - Write the number of atoms of any element in the compound in ________________ (applies to only 2 or more atoms) - “_________” will always be written at the end of the __________________ element

8. Compound Properties Compounds are formed by ________________________________. However, they do not have the properties as them. Because of chemical bonds, compounds cannot be broken down by ____________ means. They can only be broken down by __________________________________.

9. How do we name compounds? Rule 1 • Sodium chloride — made up of the elements sodium and chlorine • Zinc oxide — made up of the elements zinc and oxygen • Carbon dioxide — made up of the elements carbon and oxygen

10. Fixed Composition of Compounds For example, water (H2O) is a compound made only by joining together two atoms of hydrogen to one atom of oxygen. That is, the ratio of hydrogen atoms to oxygen atoms in water is always 2 : 1.

11. Chemical Formula of a Compound A compound can be represented by a chemical formula. • The chemical formula states • Types of atoms: hydrogen, oxygen Ratio of H to O = 2:1

12. How do we write chemical formula?Rule 1 For many compounds that contain both metallic and non-metallic elements, _______________________________________________________________________________________________________________ • calcium oxide (CaO) • sodium chloride (NaCl) • magnesium carbonate (MgCO3)

13. How do we write chemical formula?Rule 2 • water (H2O, not H2O or 2HO) • magnesium carbonate (MgCO3, not MgCO3 or MgC3O)

14. How do we write chemical formula?Rule 3 • water (H2O, not H2O1) • calcium oxide (CaO, not Ca1O1)

15. How do we write chemical formula?Rule 4 • water (H2O, not OH2) • carbon dioxide (CO2, not O2C) • nitric acid (HNO3, not O3NH)

16. Let’s try it… • How many atoms of each element are there in the compound? • Sulfuric Acid H2SO4 • __ Hydrogen • __ Sulfur • __ Oxygen • Hydrogen Peroxide H2O2 • __ Hydrogen • __ Oxygen

17. And some more formulas… • Carbon Dioxide CO2 • __ Carbon • __ Oxygen • Carbon Monoxide CO • __ Carbon • __ Oxygen • Calcium Carbonate CaCO3 • __ Calcium • __ Carbon • __ Oxygen

18. Compound Review •  A pure compound has the same elements and the same amount of elements all of the time • Elements are chemically combined • Compound properties are different from the properties of the elements • They cannot be separated physically • Physical properties such as boiling point or melting point of pure substances are do not change

19. Mixtures • A mixture is a combination of __________________________________where there is no chemical combination or reaction.

20. Mixtures combine physically in ____________________________________________. They just mix.

21. ______________________________can be combined to create a mixture.

22. Mixture Types • MIXTURES MAY BE ______________ OR ______________

23. Homogeneous Mixtures • Homogeneous Mixtures: • The prefix: "homo"- indicates ______________ • Have the same uniform appearance and composition throughout

24. Solutions • SOLUTIONS- are ____________ mixtures

25. What is a solution? • A solution is a mixture of two or more substances. • At least two substances must be mixed in order to have a solution

26. A solution has two parts • The substance in the larger amount is called the ___________ - it does the dissolving • In most common instances _______ is the solvent • The substance in the smallest amount and the one that ________ is called the ____________

27. Examples of solutions • _________ • _________ • _________ • _________

28. Heterogeneous Mixtures: • The prefix: "hetero"- indicates _____________ • A heterogeneous mixture consists of visibly different substances or phases • Two or more parts can be seen

29. Examples: • _____________ • _____________ • _____________ • _____________

30. Suspensions • A ___________ is a heterogeneous mixture of large particles • These particles are visible and will settle out on standing • Examples of suspensions are:

31. Classification of Matter

32. Compounds vs Mixtures Compounds Mixtures