Unit 2 Flashcards
Mole
A counting unit = 6.022x1023 particles
Molar mass
Mass of 1 mole of a substance (g/mol)
Balanced Equation
Tells you the mole ratio of all substances
Mole ratio
Ratio between coefficients in a balanced equation
Theoretical yield
Maximum amount of product possible
Actual yield
What you actually get in a lab
Percent yield
Actual / theoretical x 100%
Stoichiometry
Measuring amounts of reactants and products in a chemical reaction
Where is the word stoichiometry stem from?
Greek
Stoicheion means
Element
Metron means
Measure
Why does stoichiometry matter?
-Helps calculate how much of each substance is used or produced in a reaction
-based on the balanced chemical equation
Molar ratio
-Ratio of coefficients in a balanced equation
Limiting reactant
First reactant that is used up in a reaction
Excess reactant
Whatever is left over after the reaction stops because the limiting reactant got all used up
Which reactant is the first to run out during a reaction?
Limiting reactant
Formula for percent yield
Actual yield/ theoretical yield x100
Sources of error
-measurement inaccuracies
-impure reactants
-side reaction
-experimental losses
Avogadro’s number is similar to a dozen is that
It represents a specific number of items
How is the molar mass of a compound determined
By adding the atomic masses of all atoms in the compound
In percent composition, what does the “total mass of compound” refer to?
The molar mass of the compound
The mass of an element in 1 mole of a compound is used to calculate
Percent composition
How to find moles
Moles=grams/molar mass
Left over of excess
Given(excess) - needed(excess)
