2. 7.2 Writing Chemical Equations By: Jake Poserina and Tyler Dunphy

3. What is a Chemical Equation? A Chemical Equation is an expression representing a chemical reaction The reactants on the left and the formula of the products on the right These reactants are connected by an arrow called a yield Ex. Fe + O FeO

4. Symbols Used In Chemical Equations

5. Skeleton Equations A Skeleton Equation is a chemical equation that does not indicate the relative amounts of the reactants and products. Use (s) for soled, (l) for a liquid, (g) for a gas, (aq) for an aqueous solution.

6. Catalysts A catalyst is a substance that speeds up a reaction without being used up. Because a catalyst is neither a reactant nor a product, its formula is written above the arrow in a chemical equation. MnO HOHO(l)+O(g)

7. Question 1 Write a skeleton equation for this chemical reaction: when calcium carbonate is heated, calcium oxide and carbon dioxide are produced. CaCO(s)CaO(s)+CO(g)

8. Question 2 Solid sulfur burns in oxygen gas to form sulfur dioxide gas. S+OSO

9. Oxygen gas can be made by heating potassium chlorate in the presense of the catalyst manganese (IV) oxide. Potassium chloride is left as a solid residue. A. CaCO(aq)CaO+CO B. KClOKCl+MnO C. KClOMnClO+KMn D. KClO+MnOKCl+MnO

10. When solid mercury(II) sulfide is heated with oxygen, liquid mercury metal and gaseous sulfur dioxide are produced A.HgS+OHg+SOHgS+OHg+SO B.HgSHg+SOHgSHg+SO C.HgSOHg+SOHgSOHg+SO

11. Shout out to my favorite teacher @scottsweeten! #scienceproject

12. Mr. Sweetens class unit 7.2 Tyler Dunphy & Jake Poserina Homework: Write a Vendiagram on the difference's of skeletal equations, and regular chemical equations.