Balancing Equations Chemical Reactions & Equations

SPI’s: CLE Investigate chemical bonding. CLE Explore the mathematics of chemical formulas and equations. SPI Identify the reactants, products, and types of different chemical reactions: composition, decomposition, double replacement, single replacement, combustion. SPI Predict the products of a chemical reaction. SPI Balance a chemical equation to determine molar ratios.

BELL WORK Please answer the following Question with a complete sentence: Why are symbols used in Chemistry? Bell work will be taken up for a grade today!!!

Cultural Diversity El gas cloro se representa por la formula (Cl 2 ). Otros seis elmentos comunes que existen normalmente como moleculas diatomics son el hidgrogeno(H 2), el nitrogeno (N 2 ) y el fluor (F 2 ).

Objectives: Analyze chemical reactions and equations Balance chemical equations Review Chemical Changes/Law of Conservation of Mass/Matter

What is a chemical reaction (review)? Process by which atoms of one or more substances are rearranged to form different substances.

What is a Chemical Equations? A written representation of what happens during a chemical reaction. It includes chemical formulas and symbols.

What are the parts of the chemical equation? H 2 (g) + O 2 (g ) 2 H 2 O(l) Reactants Products

Symbols Used In Equations + - separates two or more reactants or products - separates reactants from products - reversible reaction (s) – solid (l) - liquid (g) – gas (aq) – water solution

Example: 2 H 2 (g) + O 2 (g) 2 H 2 O(g) 2 molecules of H + 1 molecule of O = 2 molecules of H 2 O OR 2 moles of H + 1 mole of O = 2 moles of H 2 O

Word Equations Word equations can be used to indicate reactants & products? Hydrogen (g)+Oxygen (g) Water(l)

Law of Conservation of Matter the number of times each atom appears in the reactant and product side must be equal. In a chemical equation, matter (atoms) can not be created nor destroyed.

Balancing Chemical Equations Step One: Write the Equation Step Two: Count the Atoms Step Three: Adjust Coefficients Step Four: Reduce Coefficients (if needed) Step Five: Check Your Work

In-Class Example Write a balanced chemical equation for the reaction of carbon monoxide (CO) and oxygen (O 2 ), that produces carbon dioxide (CO 2 )

Problem Solving Practice Problems Page 287 Turn in for a GRADE!!!!!

Problem Solving __N 2 + __O 2 ___N 2 O 5 __NaOH + __CaBr 2 __Ca(OH) 2 + __NaBr

Assessment: Balanced or Not 2Al + 6HCl 3AlCl 3 + 3H Not Balanced C 5 H O 2 5CO H 2 O Not Balanced

Chemical Reactions & Equations