Chapter 8a Chemistry

Chemistry is not ___, only ___ so look and act different(definition of chemical change)

Chemistry is not *magic*, only *rearrange* so look and act different(definition of chemical change)

___ yields ___

reactants/products

A ___/___ written above the arrow/yield indicates a ___ to make reaction happen quicker (meeting place for elements)

substance/symbol/catalyst

What is the rearrangement of chemicals to different patterns/groups. There are billions of these. We tried to put them in five categories.

chemical reactions

___ ___-simple substances combine to make more complex compound(80s music example)

synthesis reactions, A+B?AB

__ __-complex compounds are broken down to simpler substances(either elements or compounds) (graveyards/Hamlet quote and Shakespeare)

decomposition reactions AB?A+B

__ __-one element within a compound replaced by another element

single replacement reactions, AB+C?BC+A, AB+C?AC+B

___ ___-elements of two compounds switch partners. Like single replacement but the polyatomics stay together.

double replacement reaction, AB+CD?AD+BC

___ ___-usually organic compound (made of H and C) burns in air (oxygen) to give off the same products (carbon dioxide and water)

combustion reaction, usually: hydrocarbon+O??CO?+H?O

Combustion reactions produce lots of energy to power you (___), plants (___), and cars (___)

breathing, photosynthesis, internal combustion engine

When engines are running with too little oxygen present, it undergoes ___ ___, producting ___ rather than ___

incomplete combustion/smog(CO)/CO?

__- all atoms on left must also be on right

Law of Conservation of Mass

All equations must be balanced. Equal ___ on both sides (not necessarily equal ___ or ___).

atoms/molecules/moles

To balance equations, change coefficients in ___(never ___) of correct formula to show how many

front/middle

Guidelines for balancing equations: first, write correct ___ and leave ___ alone

formulas/subscripts

Guidelines for balancing equations: For ionic compounds use ___; covalents: ___

cross and drop/follow prefix

Guidelines for balancing equations: For single elements: ___

just write symbol-do NOT include charge for singles(don't forget diatomics)

Guidelines for balancing equations: balance using ___ so equal on both sides using trial and error

coefficients

Guidelines for balancing equations: ___ must be in lowest formula

coefficients

Guidelines for balancing equations: save _ and _ for last and __ __ to make __

H and O/double odds/evens

Guidelines for balancing equations: keep __ when counting

polyatomics