Chemical Equations EQ: What are the reactants and products of a chemical reaction? SPI

What’s a Chemical Reaction? Chemical Reaction process of a substance completely changing to a different substance with different properties.

Equations are made up of chemical symbols and formulas. Chemical Symbol Shorter way to write an element’s name. Examples: – H: Hydrogen – O: Oxygen – Fe: Iron

Chemical Formula combination of chemical symbols and numbers to represent a substance. It an easier way to write a molecules and compounds. Examples: – H 2 0: Water – CO 2 : Carbon Dioxide

Subscript Subscript the small # to the right of the element that tells the # of atoms Applies to only the element directly before it!

Examples of subscripts: –H2O–H2O – SO 4 – Ca(OH) 2

How many atoms of each?? 1. CO 2 2. H NaClF 4

Coefficients Coefficients large # to the left of the element. Applies to the whole molecule!

Examples of coefficients: – 2H 2 O – 4SO 4 – 3Ca(OH) 2

How many atoms of each?? 1. 4 NaCl 2. 6 CO H 2 O

What are reactants and products in a chemical equation?? Reactants what you start with Products what you end with

CH 4 + O 2 → CO 2 + H 2 O Circle the REACTANTS Underline the PRODUCTS

1.P 2 O 5 2.4Na(ClO) 3 How many atoms of each element are there?

CH 4 + O 2 → CO 2 + H 2 O

The Law of Conservation of Mass EQ: What is the Law of Conservation of Mass? SPI

The Law of Conservation of Mass Law of conservation of Mass states that mass cannot be created or destroyed! 4Na + 2Cl 2  4NaCl

This is important when we balance equations… An equation is balanced when the # of atoms in the reactants are = to the # of atoms in the products.

How many atoms of each element? Na + Cl 2  2NaCl

6 CO H 2 O  C 6 H O 2 Is this a balanced equation?

Is this a “balanced” equation?

You balance an equation by changing the coefficients, not the subscript!

Balance this equation. ___ Mg + ___ O 2 ___ MgO

Balance the equation. ___ H 2 O 2 ___H 2 O + ___ O 2

__ Fe + __S → __FeS

__H 2 + __O 2 → __H 2 O

__Mg + __O 2 → __MgO

_Ca + _H 2 O → _Ca(OH) 2 + _H 2

___ NH 4 NO 3  ___ N 2 O + ___ H 2 O

___BKClO 3  ___BKCl + ___BO 2

___ C 3 H 8 + ___O 2  ___ CO 2 + ___ H 2 O

__ Al 2 O 3 + __ Fe  __ Fe 3 O 4 + __ Al

___ P 4 O 10 + ___H 2 O  ___H 3 PO 4

__Al + __H 2 SO 4  __Al 2 (SO 4 ) 3 + __H 2

__Be 2 C + __H 2 O  __Be(OH) 2 + __CH 4

___ Fe + ___ O  ___ Fe 2 O 3

__S + __HNO 3  __H 2 SO 4 + __NO 2 + __H 2 O

__NH 3 + __CuO  __Cu + __N 2 + __H 2 O

__Cu + __HNO 3  __Cu(NO 3 ) 2 + __NO + __H 2 O

Al 2 (SO 3 ) 3 + NaOH  Na 2 SO 3 + Al(OH) 3