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Chemical Properties and Change

Chemical Properties and Change. Physical Properties. Physical properties are descriptions of the substance... Examples are colour, smell, mass, texture, lustre, malleability. Chemical Properties. A chemical property describes how a substance reacts with another substance

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Chemical Properties and Change

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  1. Chemical Properties and Change

  2. Physical Properties • Physical properties are descriptions of the substance... • Examples are colour, smell, mass, texture, lustre, malleability....

  3. Chemical Properties • A chemical property describes how a substance reacts with another substance • with water, oxygen, and acids • The toxicity, and combustibility

  4. Physical vs Chemical Change • Physical changes occur when the substance has been changed in some form, yet it remains the same substance chemically • For example changes of state (water and ice) • Chemical changes result in the original substance being changed to a new substance with different properties

  5. 5 Clues of a chemical change • Heat or light is given off. • A colour change • Precipitate (solid) forms in the mixture of two liquids. • Gas is produced, evidenced with bubbles in a liquid. • Change is difficult to reverse.

  6. Science Perspectives 10 • Page 178#2,3,5,7

  7. Periodic Table

  8. Bohr diagrams

  9. Bohr Diagrams

  10. Science Power 10 • Page 187#3,4

  11. Atoms and Ions • Ion is a charged atom... • by losing or gaining an electron • remember protons cannot move • Noble gases are stable: outer orbits full • Atoms will lose or gain electrons to fill outer orbit • Non metals gain electrons and become negative ions (anion) • Metals lose electrons become positive ion (cation)

  12. Science Power 10 • Page 191Try This Skills (A-E)

  13. Naming Ions • Positive ions have same name as element • Example Na+ is “sodium” • Negative ions replace endings with “ide” • Example O2- is “oxide” and F- is “fluoide”

  14. Atom and Ion

  15. Science Power 10 • Page 191#1,2,3,4

  16. Ionic Compounds

  17. Formation • Combining anions and cations • Ionic bonds always form between a metal and a non metal

  18. Formulas • 1. write the names of the symbols with ionic charges and with the metal first example aluminum and chlorine Al 3+ Cl- 2. Criss-cross the charges to determine the formula: AlCl3

  19. 3. Reduce to lowest terms if required: • Example: magnesium oxide • Mg2O2 • Reduces to MgO

  20. Naming • The name of the metal is always first. The non metal is second with the ending “ide” • Example sodium and fluorine • Sodium fluoride • Example chlorine and potassium • Potassium chloride • Example AlBr3 • Aluminum bromide

  21. Science Perspectives 10 • Page 200#2,3,7

  22. Transition Metals • Are metals located in groups 3-11 • As with other metals they form cations... However most have more than 1 stable ion • Roman numerals (in brackets after the metal name) are used to designate the charge (I=1; II=2; III=3; IV=4; V=5) • Example Copper (II) chloride...this copper ion has a charge of 2+

  23. Formulas • When determining the formulas for ionic compounds with a transition metal... • Write the symbol for the metal and then for the non-metal....determine the charges and then criss cross • NOTE: the same as for other ionic compounds except that the metal charge is indicated by the roman numeral. • Ex. Copper (II) chloride Cu 2+Cl- CuCl2 • Ex. Copper (I) Chloride Cu +Cl- CuCl • Note the charges on the Copper ions!

  24. Naming • When naming compounds with a transition metal: • Write the name of the metal and leave a space (for the roman numeral) and then write the name of the non metal ion (remember “ide” ending) • Determine the charge of the transition metal and write as a roman numeral in brackets • Ex. PbCl4 is Lead chloride • Because Cl has a 1- charge and there are 4...the charge on 1 lead ion must be 4+. • Name is then Lead (IV) chloride

  25. Practice • Write the formulas • Vanadium (IV) sulfide • Mercury (II) chloride • Manganese (IV) fluoride • Copper (II) sulfide • Write the names • CuI2 • Cu3N2 • CuO • PbI2 • SnCl4 • FeN

  26. Polyatomic Ions • Binary ionic compounds are made up of only 2 elements (one cation and one anion) • Some ions are made up of more than one element...called polyatomic ions

  27. Polyatomic Ions are made up of several non metals that share electrons but carry an overall charge Example:

  28. Common polyatomic Ions • Names generally end in “ate”

  29. Naming Polyatomic Ions • A formula with more than 2 element types • Write the name of the metal followed by the name of the polyatomic ion. • Example: NaNO3 is sodium nitrate • Practice a. Li3PO4 b. CaSO4 c. Al(NO3)3 d. KOH

  30. Writing Formulas: Polyatomic • Follow same rules as for binary compounds • Write the symbol for both ions...metal first and then polyatomic second • Write the charges (use period table and polyatomic chart) then criss cross. • NOTE: if there is more than 1 polyatomic ion in the compound its formula is in brackets with the subscript outside the bracket. • Example: Aluminum nitrate Al3+ NO3- • there are 3 nitrate ions Al(NO3)3

  31. Practice Formulas • Magnesium chlorate • Potassium carbonate • Aluminum hydroxide • Lithium sulfate • Berylium phosphate

  32. Quiz

  33. Hazards and Safety

  34. WHMIS: Workplace Hazardous Materials Information System - symbols - MSDS (material safety data sheets) • HHPS: Hazardous Household Product Symbols

  35. Chemical Change Lab

  36. Ions Lab

  37. Molecular Compounds

  38. Molecular compounds are made up of individual molecules... • ionic compounds have many ions in a specific ratio arranged in a crystal • Metals (lose electrons) and non-metals (gain electrons) join to form ionic compounds

  39. Lithium oxide

  40. Covalent bonds • Non-metals will combine to form molecular compounds by sharing electrons • Shared outer electrons form a covalent bond between elements • Diatomic molecules have just 2 atoms

  41. Diatomic molecules • Fluorine

  42. Diatomic molecules • Oxygen

  43. # Covalent bonds • The number of covalent bonds depends on the number of the number of valence electrons (outer shell). • Example: Chlorine has 7...therefore 1 electron needed = 1 covalent bond (one shared-pair) • Determine the number of bonds for: • Fluorine, carbon, nitrogen, silicon, oxygen, hydrogen, sulfur

  44. Many-many-many-more • Are made up of 3 or more atoms. • H2O , N2O, NO2, CO2, CH4, CH3OH, C2H6, C6H12O6 , SO2 ....

  45. Naming and Formulas • Prefixes indicate number of atoms • Mon(o) =1 Monoxide • Di =2 Dioxide • Tri =3 Trioxide • Tetra =4 Tetrachloride • Penta =5 Pentafluoride

  46. Naming • Write names of elements in same order as in the chemical formula. • Second element has ending “ide” • Add prefixes...except “mono” is not used for the element. • Example PCl3 • Phosphorous trichloride • Example SiO2 • Silicon dioxide

  47. Formulas • Given the name: write the element symbols in same order and prefixes become subscripts

  48. Homework • Page 212#1-4,6,7,9

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