CHEMICAL REACTIONS Flashcards
Describe the changes that occur as a part of a chemical reaction
color change formation of a precipitate formation of a gas odor change temperature change
What are the standard aspects of a chemical equation?
- Reactants on the left hand side and products on the right
- Physical states denoted as subscripts in brackets
- The delta sign can be placed above the arrow in between products and reactants if reactants are heated
How to balance a chemical equation
- Write out the unbalanced equation with all molecules or atoms involved
- Count out the number of each atom either side, apply coefficients as necessary until they are the same either side
- include the states as subscripts
Describe conservation of mass in terms of atoms
No atom is created or destroyed in a chemical reaction therefore, once a reaction has taken place, the total mass of the reactants should equal the total mass of the products
What is a combination reaction?
Two or more reactants combine to yield a single product
What is a decomposition reaction?
1 reactant splits into 2 or more products
What is a single replacement reaction?
One element replaces another element in a molecule
What is a double replacement?
Two elements replace each other in molecules
What is a combustion reaction?
Carbon compound burns in oxygen gas to form CO2 and H2O, energy is released as a product in the form of heat
What is a polymerisation reaction?
Molecules join to form a long chain
What is a redox/oxidation-reduction reaction?
Electrons are transferred from 1 substance to another, oxidation is the loss of electrons, reduction is the gaining of electrons
Describe exo and endothermic reactions
Exothermic: energy is transferred from system to surrounding
Endothermic: energy is transferred from the surrounding to the system
