C3.1 Introducing chemical reactions Flashcards
Avogadro constant
the number of entities in one mole, equal to the number of atoms in 12.0 g of 12C atoms, 6.02 × 1023
balanced equation
a model for a reaction showing formulae and number of units for all substances involved. The numbers of each atom are the same on both sides of the equation
closed system
apparatus in which substances cannot enter or leave the reaction mixture during a reaction
compound ion
an ion formed when a group of atoms loses of gains electrons
diatomic molecule
molecule containing two atoms
excess
when a reactant is present in an amount greater than that needed to react with the other reactant
half equation
a type of chemical equation that models the change that happens to one reactant in a reaction
ionic equation
a type of chemical equation that models how oppositely charged ions form an ionic compound
law of conservation of mass
the principle that states that the total mass stays the same during a chemical reaction, because atoms are not created or destroyed during a chemical reaction
limiting reactant
a reactant present in an amount less that that needed to react completely with the other reactant in a chemical reaction
molar mass
the mass in grams of one mole of a substance
mole
amount of substance that contains the same number of particles (6.02 × 1023) as there are atoms in 12.0 g of 12C