chemical reactions (book) Flashcards
What is a chemical reaction?
a process during which substances are changed into one or more new substances
What are some signs that a chemical reaction has taken place? (6)
- change in color
- change in temp
- formation of a gas
- formation of a precipitate
- change in odor
- light produced
What does the coefficient mean in a chemical reaction?
refers to the number of moles of that atom/molecule
What is the law of conservation of energy? What does it mean in terms of chemical reactions?
Matter can’t be created or destroyed in reactions
so the mass of the products have to equal the mass of the reactants
and the number of moles of each element has to be the same on both sides
What is a synthesis/combination reaction?
where 2+ substances combine to make a new product
What is a decomposition reaction?
Where a substances breaks down into 2+ substances
What is a single replacement reaction?
An element in a compound is replaced by another element. metal cations replace other metal cations, nonmetal anions replace nonmetal anions
(ex: AB+C -> AC+B)
What is a combustion reaction?
A reaction where oxygen reacts with all the elements in the original compound to form oxides
(ex: CH4+2O2 -> CO2 + 2H2O
What is a double replacement reaction?
Where two compounds react in an aqueous solution and the anions and cations switch places to form new products
What is a redox reaction?
The transfer of electrons between two substances, changes the oxidization states of an atom/ion/molecule
(ex: Zn + 2H+ -> Zn2+ + H2)
What is stoichiometry?
The calculation of reactants and products in a chemical reaction
