AND Types of Reactions Let the fun begin!

Why do we need to balance equations? To satisfy the Law of Conservation of Mass Which says: Matter cannot be created or destroyed; therefore, You must have the same number of atoms on each side of a chemical equation to show conservation of mass. ie. Reactants = Products

Step 1 Make sure compounds are balanced; In this reaction, the reactant compounds’ charges are not balanced: Na +1 O -2 + Ba +2 Cl  Na +1 Cl -1 + Ba +2 O -2 Use subscripts to balance the compounds to zero: Na 2 O + BaCl 2 -  NaCl + BaO ( +2)+(-2) = 0 ( +2)(-2) = 0

Step 2 Use coefficients to balance the numbers of atoms on each side; Na 2 O + BaCl 2 -  NaCl + BaO How many sodiums on the left? 2; how many on the right/ 1; put a coefficient 2 in front of the one on the right. How many oxygens on the left/ on the right/, etc. Na 2 O + BaCl 2 -  2NaCl + BaO

Step 3: Check to Insure the same number of atoms on both sides Na 2 O + BaCl 2 -  2NaCl + BaO Atom Left Right Na 2 2 O 1 1 Ba 1 1 Cl 2 2 Balanced! Mother Nature would be proud! Great job!

Let’s Practice! Balance this equation: Al + CuCl  AlCl 3 + Cu How many aluminum atoms on the left? On the right? How many copper atoms on the left? On the right? How many chlorine atoms on the left? On the right? Use coefficients to balance each atom!

Answer: 2Al + 3CuCl  2AlCl 3 + 3Cu

Balance this equation: Na 3 PO 4 + CuSO 4 -  Na 2 SO 4 + Cu 3 ( PO 4 ) 2

Answer: Na 3 PO 4 + CuSO 4 -  Na 2 SO 4 + Cu 3 ( PO 4 ) 2 First ask, “how many sodiums on the left, how many sodiums on the right?” Use coefficients to balance each of the atoms left to right. 2Na 3 PO 4 + 3CuSO 4 --  3Na 2 SO 4 + Cu 3 (PO 4 ) 2

Balance this equation: C 4 H 10 + O  CO 2 + H 2 O + E

Answer: C 4 H O  4CO 2 + 5H 2 O + E

What does it really look like on a molecular level? N 2 + H  NH 3

The molecules would look like this: N 2 + H 2  NH 3

If the equation is balanced? You need to show the same number of atoms on each side of the arrow: N 2 + 3H 2  2 NH 3

Practice More! Try this helpful link: S/fbeqns/chemeqnf.htmhttp://newtraditions.chem.wisc.edu/FPT S/fbeqns/chemeqnf.htm

Types of Reactions Why? They help you predict products. Synthesis (direct combination) Decomposition Single Replacement Double Replacement Combustion Acid Base Neutralization

Synthesis (direct combination) A + B  AB

Decomposition AB  A + B

Single Replacement AB aq + C s  CB aq + A s

Double Replacement AB aq + CD aq  CB s + AD aq

Combustion C x H x + O 2  CO 2 + H 2 O + E (hydrocarbon)

Acid Base Neutralization Acid + Base  Salt + Water HA + BOH  BA + H 2 O

Balancing Equations: or

Definitely HOT!

The End … of this slide show, but just the beginning of more chemistry!