unit 2 chemical reactions Flashcards
what is the evidence of a chemical change
1) change in colour
2) formation of gas
3) formation for precipitate
4) release/absorbtion of heat
5) difficult to reverse
what is a chemical change
-change in which a new substance is formed
what is collision reaction theory
-chemical reactions involve collisions and rearrangements of atoms or groups of atoms
-the outcome depends on the energy and orientation of the collisions
why do we balance equations
-to obey the law of conservation of mass
what is the law of conservation of mass
-must have the same number of atoms on each side of equation
what are the five types of reactions
-synthesis
-decomposition
-combustion
-single displacement
-double displacement
what is a synthesis reaction
two or more reactants combine to produce a new product
what is a decomposition reaction
-a compound breaks down into two or more simpler compounds or elements
what is a combustion reaction
-the rapid reaction of a substance with oxygen to produce oxides and energy
hydrocarbon + oxygen —> carbon dioxide + water + energy
what is an incomplete combustion reaction
-occurs when oxygen supply is limited
-may involve the release of carbon monoxide, carbon, carbon dioxide, soot (C8H), water, and energy
what is a single displacement reaction
-one element takes the place of another element in a compound
-metal only takes place of metal and non metal only takes place of non metal
-metal with only displace a metal listen below it on the activity series
what is a double displacement reaction
-the cations and anions of aqueous solutions rearrange
-neutralization is a double displacement reaction
what are the three possible outcomes of a displacement reaction
-production of a participate
-production to a gas
-production of water
define solute
the substance that dissolves in solvent
define solvent
the substance that dissolves in a solute
