Activator H 2 + O 2  H 2 O 1.What is this chemical equation showing the formation of? 2.Do you think this equation is balanced? Why?

Chemical Reactions SPS2. Students will explore the nature of matter, its classifications, and its systems for naming types of matter. d. Demonstrate the Law of Conservation of Matter in a chemical reaction. Purpose: Determine why chemical equations have to be balanced.

Chemical Reaction A process that involves a rearrangement of atoms, molecules, or ions. Substances react together to form new substances with different properties. Examples: Rust, formation of table salt and water

Chemical Equations Reactants → Products –Reactants are the substances that undergo change. Products are the new substances produced from the change. Using Equations to Represent Reactions –Hydrogen + Oxygen → Water –A chemical equation is a representation of a chemical reaction in which the reactants and products are expressed as a formula.

The mass of the products is always equal to the mass of the reactants. Mass is neither created nor destroyed in a chemical reaction. Law of Conservation of Matter

Balancing Equations Water is formed by the reaction of hydrogen with oxygen. –H 2 + O 2 → H 2 O, if you look at this closely, you will notice the number of O’s on each side is not the same. In order to show that mass is conserved during a reaction, a chemical equation must be balanced.

Equations can be balanced by changing the coefficients, the numbers that appear before the formulas. The first step to balancing an equation is to count the number of atoms of each element on each side of the equation. –2H 2 + O 2 → 2H 2 O, the equation is now balanced. Balancing Equations

Chemical Calculations Think about baking. A cake recipe tells you how much of each ingredient is needed to bake one cake. What if you want to make three cakes? Chemical equations can be read as recipes for making new substances.

Chemical Calculations 2H 2 + O 2 → 2H 2 O Two molecules of hydrogen react with one molecule of oxygen and form two molecules of water. Two moles of hydrogen react with one mole of oxygen and form two moles of water. 4.0 grams of H 2 reacts with 32.0 grams of O 2 and forms 36.0 grams of H 2 O

Chemical Calculations In chemical reactions, the mass of a reactant or product can be calculated by using a balanced chemical equation and molar mass of the reactants and products. Reactants → Products unbalanced H 2 + O 2 → H 2 O balanced 2H 2 + O 2 → 2H 2 O

Balancing Chemical Equations Using the Tile Method __ N 2 + __ H 2  __ NH 3 N2N2 H2H2 H2H2 H2H2 NH 3 2 3

__ Na 2 O 2 + __ H 2 O  __ NaOH + __ O 2 2 Balancing Chemical Equations Using the Tile Method Na 2 O 2 H2OH2ONaOHO2O2 H2OH2O Na 2 O 2 2 4

Activator Create a KWL chart for Chemical Reactions KnowWant to Know Learned

What is a chemical reaction? A process in which atoms of the same or different elements rearrange themselves to form a new substance. While they do so, they either absorb or give off heat. Reactants → Products –Reactants are the substances that undergo change. Products are the new substances produced from the change.

What is a chemical equation? A representation of a chemical reaction in which the reactants and products are expressed as formulas. Using Equations to Represent Reactions –Hydrogen + Oxygen → Water

Law of Conservation of Matter The mass of the products is always equal to the mass of the reactant. Mass is neither created nor destroyed in a chemical reaction

Activator Balance the following equation ___ H 2 + ___ O 2  ___ H 2 O H2H2 O2O2 H2OH2O H2OH2O H2H2 22

Balancing Chemical Equations Atom Inventory Method SPS2d. Demonstrate the Law of Conservation of Matter in a chemical reaction.

1. Write the chemical equation. C 3 H 8 + O 2  H 2 O + CO 2

2. List types of atoms present in the equation. C 3 H 8 + O 2  H 2 O + CO 2 Reactants Products C H O

3. Count the number of atoms for each element; reactants then products. C 3 H 8 + O 2  H 2 O + CO 2 Reactants Products C 3 1 H 8 2 O 2 3

4. Start with the first atom (C) and add coefficients to balance C 3 H 8 + O 2  H 2 O + 3CO 2 Reactants Products C H 8 2 O 2 3 7

5. Now balance the second atom (H) by adding a coefficient. C 3 H 8 + O 2  4H 2 O + 3CO 2 Reactants Products C H O

6. Now balance the last atom type (O). C 3 H 8 + 5O 2  4H 2 O + 3CO 2 Reactants Products C H O

Balance the following 1.___ S 8 + ___ O 2  ___ SO 3 2.___ HgO  ___ Hg + ___ O 2 3.___ Fe + ___ O 2  ___ Fe 2 O 3 4.___ K + ___ Br 2  ___ KBr 5.___ H 2 O 2  ___ H 2 O + ___ O 2

Balance the following 6.___ KClO 3  ___ KClO 4 + ___ KCl 7.___ P 4 O 10 + ___ H 2 O  ___ H 3 PO 4 8.___ Sb + ___ O 2  ___ Sb 4 O 6 9.___ N 2 + ___ H 2  ___ NH 3 10.___ N 2 + ___ O 2  ___ N 2 O

Balance the following 11.___ Zn + ___ HCl  ___ ZnCl 2 + ___ H 2 12.___ Na + ___ H 2 O  ___ NaOH + ___ H 2 13.___ C 10 H 16 + ___ Cl 2  ___ C + ___ HCl 14.___ Fe 2 O 3 + ___ H 2  ___ Fe + ___ H 2 O 15.___ C 7 H 16 + ___ O 2  ___ CO 2 + ___ H 2 O

16. ___ SiO 2 + ___ HF  ___ SiF 4 + ___ H 2 O 17. ___ KClO 3  ___ KCl + ___ O ___ C 3 H 8 + ___ O 2  ___ CO 2 + ___ H 2 O 19. ___ Fe 2 O 3 + ___ CO  ___ Fe + ___ CO ___ PCl 5 + ___ H 2 O  ___ HCl + ___ H 3 PO 4 Balance the following

21. ___ H 2 S + ___ Cl 2  ___ S 8 + ___ HCl 22. ___ Fe + ___ H 2 O  ___ Fe 3 O 4 + ___ H ___ CO 2 + ___ H 2 O  ___ C 6 H 12 O 6 + ___ O ___ SiCl 4 + ___ H 2 O  ___ H 4 SiO 4 + ___ HCl 25. ___ H 3 PO 4  ___ H 4 P 2 O 7 + ___ H 2 O Balance the following

What is wrong with... H 2 + O 2  NaOH 2H 2 + O 2  2H 2 O

#1 Balance ____ Na + ____ Cl 2  ____ NaCl

#2 Balance ____ H 2 O  ____ H 2 + ____ O 2

#3 Balance ____ CaCO 3  ____ CaO + ____ CO 2

#4 Balance ___ Cu + ___ AgNO 3  ___ Ag + ___ Cu(NO 3 ) 2

#5 Balance ___ K + ___ H 2 O  ___ H 2 + ___ KOH

#6 Balance ___ Pb(NO 3 ) 2 + ___ KI  ___ PbI 2 + ___ KNO 3

#7 Balance ___ CaCO 3 + ___HCl  ___CaCl 2 + ___ H 2 CO 3

#8 Balance ___ HCl + ___ NaOH → ___ H 2 O + ___ NaCl

#9 Balance ___ Mg + ___ O 2 → ___ MgO

#10 Balance ___ MgCO 3 → ___ MgO + ___ CO 2

#11 Balance ___ KNO 3 → ___ KNO 2 + ___ O 2

#12 Balance ___AgNO 3 + ___NaCl → ___NaNO 3 + ___AgCl

#13 Balance ___ Ag + ___ S → ___ Ag 2 S

#14 Balance ___ Cl 2 + ___ KBr → ___ KCl + ___ Br 2

#15 Balance ___ H 2 + ___ O 2  ___ H 2 O

#16 Name the Compound N2O3N2O3

#17 Name the Compound Al 2 O 3

#18 Write the Formula Iron (IV) Oxide

#19 Write the Formula Potassium Phosphide

#20 Write the Formula Diboron Pentaoxide