spi 0807.9.10 reactants & products spi 0807.9.11 law of conservation of mass

Chapter 7SPI 0807.9.10 Reactants & ProductsSPI 0807.9.11 Law of Conservation of Mass Bellwork

1

Turn to page 340, and read the 3rd paragraph about reactants and products.1) Contrast reactants and products (how are they different?)2) Look at the formula below. Identify the reactants and products

C + O2 CO2


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1) Contrast reactants and products (how are they different?)Reactants-starting materials in a chemical reactions Always written before the arrow

C + O2 CO2


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1) Contrast reactants and products (how are they different?)Reactants-starting materials in a chemical reactionsProducts-substances formed in a chemical reaction Always written after the arrow

C + O2 CO2

Chapter 7 SPI 0807.9.10 Reactants & ProductsSPI 0807.9.11 Law of Conservation of Mass

3 key TopicsChemical symbolsChemical FormulasChemical Equations

Notes


Key TopicsChemical symbols

Notes

Examples: H is just a chemical symbol (for the element hydrogen)O is just a chemical symbol (for the element oxygen)


Key TopicsChemical formulas

Notes

Chemical symbols combined together = chemical formulas

Examples: Put the symbols H and O together…And you get the formula for water… H2O

Chapter 7 SPI 0807.9.10 Reactants & ProductsSPI 08079.11 Law of Conservation of Mass

Key TopicsChemical symbols & Chemical Formulas

Notes

Very Important!!!symbols & formulas must be written correctly. CO2= one carbon atom, two oxygen atomsCO= one carbon atom, one oxygen atomCo=one cobalt atom2CO= two carbon atoms, two oxygen atoms2CO2= two carbon atoms, four oxygen atoms



Notes

QUICK REVIEW!

CO2

Is this a chem symbol or chem formula?Is this a mixture or a compound? How many total atoms does it contain?Identify the individual atoms.



Notes Nov 5, 2012

QUICK REVIEW!

CO2

Is this a chem symbol or chem formula?It is a chemical formula



Notes

QUICK REVIEW!

CO2

Is this a mixture or a compound? It is a compound



Notes

QUICK REVIEW!

CO2

How many total atoms does it contain?Three



Notes

QUICK REVIEW!

CO2

Identify the individual atoms.

= one carbon atom, two oxygen atoms


Key TopicsChemical Equations

Notes

Chemical formulas combined together = chemical equations

Examples:Equation: 2H2 + O2 2H2O

Equation: 2Na + Cl2 2 NaCl


2 parts of chemical equations (1) reactants (2) productsReactants: are the things you are combing together…the things you start with in a chemical reaction

Products: are the things that you produce in a chemical reaction… the things you end up withExample: 2H2 + 02 2H20

Reactants (H & O) Products (water)

Notes


Chemical Equations show how chemical reactions occur, and the must obey the law of conservation of mass

The law of conservation of mass: Atoms are never lost or gained in a chemical reaction, they are just rearranged.

Example: Look at the following equation. It does not obey the law of conservation of mass and is called unbalanced

(count the atoms on each side!) H2 + O2 H2O

2 & 2 2 & 1 Four is not equal to three!

Notes


Balancing Equations: make sure the number of reactants atoms equals the number of products atoms. If they are not equal, you must balance the equation

(See below for an example)Same equation, but now I have balanced it

(count the atoms on each side)2H2 + O2 2H2O

Coefficient=number in front of a chemical symbol or formula (tells you to multiply) Subscript=small number below and to the right of a chemical symbol (tells you the number of atoms)

Notes

4 Hyd + 2 Oxy yields 4 Hyd and 2 Oxy6 reactant atoms is equal to 6 product atoms!

spi 0807.9.10 reactants & products spi 0807.9.11 law of conservation of mass

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