Chapter 3 - Chemical Reactions Flashcards
Chemical reactions
changes in arrangements of electrons
process that generates a substance that was not previously present in that system
Evidence of a chemical reaction
solid precipitate formed colour change gases released energy released or absorbed (heat) change in odour
Law of conservation of mass
during a chemical reaction, matter is neither created nor destroyed
this means that the number of atoms in each reaction must be the same and are balanced using coefficients
Representing chemical change
word, chemical, ionic, net ionic
word equation = representation using only the names of the chemicals involved
chemical equation = representation that indicates the chemical formulas, relative number of entities, and states of matter of the reactants and products
ionic equation = a chemical equation that also indicates the charges and valence electrons of each reactant and product
net ionic equation = a chemical equation that only indicates the particles that are actually reacting (no spectator ions)
Kinetic molecular theory
all matter is made up of particles
these particles are in continuous random motion
temperature is a measure of the average speed of the particles
Collision-reaction theory
chemical reactions involve collisions and rearrangements of atoms
the outcome of collisions depends on the energy and orientation of the collisions
Combustion
synthesis reaction where oxygen is one of the reactants
oxides are always part of the products as well as energy
an incomplete combustion reaction leads to products that are not fully oxidized
three things must be present in order for a combustion reaction to occur = fuel, oxygen, and heat
Synthesis
a chemical reaction in which two or more substances combine to form a more complex substance
these reactions occur in order to stabilize the atoms, as the electrons have less potential energy
Decomposition
a chemical reaction in which a compound is broken down into two or more simpler substances
the products of these reactions may not always be into the most simple elements
electrical current can be used to reverse the synthesis process
Single Displacement
the reaction of an element with a compound to produce a new element and a new compound
elements will only react if = the two reactants are in contact, the reactant particles are mobile enough to collide with sufficient kinetic energy, and based on the activity series
Metal reactants in a SD reaction
metal with no charge needs to lose electrons to react
metal with a positive charge, and therefore an empty valence shell, can accept electrons
non-metal with a negative charge, and therefore a full valence shell, cannot accept any electrons
Non-metal reactants in a SD reaction
non-metal with no charge needs to gain electrons to react
metal with a positive charge, and therefore an empty valence shell, has no electrons to lose
non-metal with a negative charge, and therefore a full valence shell, will lose a valence electron if it has a lower electron affinity than the reactant
Chemical battery
circuit component that separates the 2 half reactions of a single displacement reaction into 2 different compartments
produces a measurement of potential difference, and is therefore a quantitative value in order to compare two elements
Double displacement
a reaction in which aqueous ionic compounds rearrange cations and anions, resulting in the formation of a new compound
electron transfer is not occurring in these reactions
a reaction only occurs if one of the products is a low solubility substance or a molecular substance
Identification of ions in a solution
solution colour
flame test
double-displacement reaction tests
