Unit 3 Flashcards
Particle
Smallest unit that is represented by a chemical formula
What is an atom?
A single symbol
Ex. Ne
What is a molecule ?
More then one covalent atom bonded together
What is a formula unit?
An ionic compound made of multiple particles including ionic and covalent atoms.
What is an ion?
An atom, molecule, or formula unit with a charge.
What is formula mass?
Atoms+Simple ions (atomic mass)
For entities with more then one atom, sum of all masses in the formula
How do you calculate formula mass?
Add mass of all atoms in formula using the mass given on the period table.
What is % composition?
Relative mass of each element in a compound.
How do you find the % composition.
Divide the mass of an element by the mass of the compound and multiply by 100.
Law of definite proportions
The elements in a chemical compound are always present in the same proportions by mass.
Stoichiometry
Numerical relationship between reactants and products in a chemical reaction
Particle Ratio
Coefficients in a balanced chemical equation
Equation to use particle ratio to find unkown quantities
unknown= known x unknown coefficient/known coefficient
What is a Limiting Reactant?
Reactant that is completely consumed during a chemical reaction, limiting the amount of product produced
What is a Excess Reactant(s)?
Reactants that are partially consumed by a reaction
What is Avogadro’s Constant?
1 mole= 6.02 x 10(23) particles
Mole Ratio is equal to what?
Particle ratio
If the formula mass of carbon is 12 Da what is the molar mass?
12g/mol of carbon
What is a mole?
The quantity of matter with a mass in g equal to its formula mass in Da
What is molar mass?
The mass of one mole of any substance
Equation for moles to mass
Mass= (quantity in mol) x (molar mass g/mol)
Equation from mass to quantity in mols
Quantity in mol = mass/ molar mass g/mol
When do you use mass stoichiometry?
When given a chemical equation and amount in grams.
What is the line equation for mass stoichiometry?
Grams of known element x 1 x # of mols of unknown x formula mass of unknown/ formula mass of known/ # of mols of known/ 1
What is yield?
Quantity of product produced from a given quantity of the limiting reactant
What is theoretical yield?
-The amount of product predicted by stoichiometry
-maximum yield
-LR is completely consumed
-mass to mass calculation
How do you find out theoretical yield?
Using the equation for mass stoichiometry
What is actual yield?
Measured quantity obtained in a real chemical equation
How to calculate % yield
actual yield/ theoretical yield x100%
How to calculate actual yield
% yield/ 100% x theoretical yield
What is the empirical formula?
Shows the lowest whole-number ratio of atoms of each element in a compound.
What is the molecular formula?
Gives the actual number of atoms in each element in a compound.
How to find empirical formula ?
Divide the mass in g of every element by the mass in Da
The lowest number is 1
How to find molar mass?
Add atomic mass of every atom
