Chemical reactions Flashcards
When describing matter explain its…
properties/characteristics and how it changes
physical property
a characteristic of a substance that can be observed without changing the substance
chemical property
a characteristic of a substance that describes its ability to change into other substances
physical change
any change that alters the form/appearance of a substance but does not make the substance into another substance
chemical change/reaction
atoms rearranging to form new substances with different chemical/physical properties
reactants
substances that undergoes a change in a chemical reaction
products
t he product of a chemical reaction
chemical changes occur when bonds…
break/form that produces new substances
chemical reactions involve changes in…
properties and changes that you can observe
to detect chemical reactions observes changes in…
properties of the metals involved
precipitate
a solid that form from a solution during a chemical reaction
chemical reactions absorb or liberate…
heat
breaking bonds require…
energy
endothermic reaction
making/breaking of bonds resulting in an absorption of energy
Exothermic reaction
making/breaking of bonds in a result of a net release in energy
chemical equations
a short, easy way to show a chemical reation, using symbols instead of words that have a common structure
the number of reactants and products can vary while some…
only have one
a chemical equation tells you the substance that you…
start and end with in a reaction
conservation of matter
principal that states that matter is neither created or destroyed during a chemical reactoin
the number of atoms stays the same no matter how…
they’re arranged in a chemical reaction
open system
matter can enter or escape to its surroundings
closed system
matter is not allowed to enter or leave
to describe a reaction accurately, chemical equation must show the same…
number of elements on either side
coeffecient
a number placed in front of a chemical formula
the three general types of chemical reactions are…
synthesis, decomposition, and replacement.
synthesis
when 2 or more elements/compounds combine to make a more complex substance
deocmposition
when compounds break into simpler products
replacement
when one element replaces another in a compound
in a double replacement reaction, elements in one compounds trade places with…
elements in another compound
a reaction cannot begin if the reactants have enough…
energy to break their chemical bonds
activation energy
the minimum amount of energy needed to start a chemical reaction
all chemical reactions require a certain amount of…
activation energy to get started
every chemical reaction needs…
activation energy
it depends on if a reaction is exothermic or endothermic to determine of the reactions needs…
more energy or notf
actors that affects rates of a reaction include…
surface area, temperature, concentration, and the presence of catalysts and inhibitors
chunks of solid + liquid or gas = particles on the…
surface of a solid that come into contact with other reactants
breaking a solid into smaller pieces makes more particles become…
exposed and makes the reaction happen faster which could be dangerous
when heating a reaction, the particles move faster increasing the reaction rate in two ways:
- particles come in contact more often, more changes for reactions to happen
- faster moving particles have more energy which causes more particles to get over the activation energy “hump”
concentration
the amount of a substance in a given volume
increasing the concentration of reactants supplies more…
particles to react
catalyst
a material that increases rate of reaction by lowering activation energy
enzymes
biological catalysts in cells
inhibitor
a material used to decrease the rate of a reaction
combustion
a rapid reaction between oxygen and fuel that is exothermic
fuel
a material that releases energy when it burns
what is in the fire triangle
heat, fuel, and oxygen
