Download presentation
Presentation is loading. Please wait.
Published byStephany June White Modified over 8 years ago
1
UNIT REVIEW:
2
Chemicals & Their Properties Chemicals & Their Reactions Acids & Bases
4
Chemical Periods and Groups Row – period Column – group 4 best known groups ▪ Group 1: Alkali Metals ▪ Group 2: Alkaline Earth Metals ▪ Group 17: Halogens ▪ Group 18: Noble Gases
5
Proton Positive charge, located in nucleus Neutron Neutral, located in nucleus Electron Negative charge, orbit around nucleus
6
Electron orbit shown as ring around nucleus 1 st orbit – 2 electrons 2 nd & 3 rd orbit – can old maximum of 8 electrons Example: Sodium
7
An ion is an atom that has become charged by gaining or losing electrons Positive ion - cation Negative ion - anion
8
Ionic Compound A compound made up of one or more positive metal ions (cations) and one or more negative non-metal ions (anions) Example: sodium chloride
9
Made up of 2 elements: metal and non-metal Keep name of metal, change end of non- metal to “ide” Writing compounds: criss-cross rule Examples: Magnesium chloride Aluminum oxide
10
Copper (I) or Copper (II) Iron (II) or Iron (III) Lead (II) or Lead (IV) Maganese (II) or Maganese (IV) Tin (II) or Tin (IV) *PRACTICE Page 200 #9
11
An ion made up of more than one atom that acts as a single particle Page 202 - Table 1: Formulas and Names of Common Polyatomic Ions Examples: Sodium carbonate Iron (III) nitrate Ca(OH) 2 *PRACTICE Page 205 #1,2
12
Molecular compound - a pure substance formed by two or more non-metals Covalent bond - a bond that results from atoms sharing electrons Diatomic molecules - molecule consisting of only 2 atoms of either the same or different elements Table 1 Page 208 Common Diatomic Molecules HOFBrINCl Table 2 Page 298 Common molecular compounds
13
Mon(o)- = 1 Di- = 2 Tri- = 3 Tetra- = 4 Penta- = 5 *PRACTICE Page 212 #3 (Ionic or molecular?)
15
Word equations - writing names of products and reactants Chemical equations - using chemical formulas of products and reactants Reactant - a chemical, present at the start of a chemical reaction that is used up during a reaction Product - a chemical that is produced during a chemical reaction State symbols in chemical reactions: (s) solid, (l) liquid, (g) gas, (aq) aqueous - dissolved in water
16
Law of conservation of mass - in any given chemical reaction, the total mass of the reactants equals the total mass of the products Chemical equations obey the law of conservation of mass - the number of atoms of reactants are still present in the products Coefficients are added before chemical formulas in a chemical equation to ensure the number of atoms on each side of arrow are equal (balanced)
17
Step 1: Word equation Step 2: Replace each chemical name with the correct chemical formula Step 3: Count the number of atoms of each type on either side of the arrow Step 4: Multiply the formulas by an appropriate coefficient until all the atoms are balanced. Keep checking whether the numbers of each type of atom on both sides are balanced. NOTE: Because polyatomic ions generally stay intact, you can count polyatomic ions in the same way you count atoms Step 5: The balanced chemical equation *PRACTICE Page 236 #5, 7
18
SYNTHESIS REACTIONS Two simple reactants combine to make a larger or more complex product General pattern: A + B → AB DECOMPOSITION REACTIONS Reaction in which a large or more complex molecule breaks down to form two (or more) simpler products General pattern: AB → A + B
19
SINGLE DISPLACEMENT REACTIONS A reaction in which an element displaces another element in a compound, producing a new compound and a new element General equation A + BC → AB + C DOUBLE DISPLACEMENT REACTIONS A reaction that occurs when elements in different compounds displace each other or exchange places, producing two new compounds General equation AB + CD → AD + CB
20
COMBUSTION Complete combustion: hydrocarbon + oxygen → carbon dioxide + water + energy Incomplete combustion also produces carbon monoxide and soot Other combustion reactions: element + oxygen → oxide + energy CORROSION The breakdown of metal as a result of chemical reactions with the environment Rust - corrosion of metals containing iron Causes of rust - oxygen, water, electrolytes Preventing corrosion - protective coatings, corrosion resistant materials, galvanizing
21
*PRACTICE Page 258 # 7
23
Properties of Acids Acids - an aqueous solution that conducts electricity, tastes sour, turns litmus red and neutralizes bases Molecular compounds - become ions in water - conduct electricity (H+ ions) Chemical formulas of acids - begin with H and end with (aq) Names of acids ▪ Binary acids - only contain 2 elements (Table 1 Page 269) ▪ Oxyacids - related to polyatomic ions (Table 2 Page 269)
24
Properties of Bases Bases - aqueous solution that conducts electricity, tastes bitter, and turns litmus blue Electrolytes - form ions when dissolved in water Names and Formulas of Bases (Table 4 Page 271) Acid-base indicator A substance that changes color depending on whether it is in an acid or a base ▪ Table 3 Page 270 - Bromo blue, Phenophthalein, Litmus
25
pH is a measure of how acidic or basic a solution is pH scale is a numerical scale of all the possible numerical values of pH from 0-14 used to compare the acidity of solutions Neutral - neither acidic or basic, with pH of 7 Solution with pH less than 7 considered acidic Solution with pH greater than 7 considered basic
26
Occur when an acid and a base react to form products with pH closer to 7 than either of the reactants Products are an ionic compound (sometimes called a “salt”) and water Acid + Base → Water + Ionic Compound Applications: Chemical Spills Antacids
27
Acid precipitation - term used to describe any precipitation (rain, snow, fog) that has become acidic from reacting with compounds in atmosphere Pollutants - sulfur oxides and nitrogen oxides - combine with water in atmosphere Acid rain has pH less than 5.6 (normal rain) Source of pollutants - Combustion of fossil fuels Environmental Impact of Acid Precipitation Aquatic Ecosystems, Soils, Forests Economic Impact Damage to structures, buildings, and monuments
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.