Chemistry Formulas chapters 1-3
Molarity to Mass steps
1) first find the molar mass of the given compound 2) multiply the liters of solution times the given molarity over 1 liter to get molarity 3) Multiply the molarity you recieved times the molar mass of 1 mole to get grams the final answer
Empirical formula to molecular formula
1) to determine the molecular formula you need to know the empirical formula and the molar mass of the compound 2) divide the given molar mass of the molecular formula/ the molar mass of the empirical formula 3) when you divide you will get a whole number multiplying factor as your answer 4) Multiply the empirical formula subscripts times the multiplying factor to get the molecular formula
Calculating the final concentration and volume
1) use the formula m1 v1= m2 v2 2) plug in the given initial and final amounts 3) solve for missing value in formula
From percent composition to empirical formula
1). Find the empirical formula 2) change percent to grams 3) change grams to moles by multiplying the grams times 1/ molar mass 4) Divide by the smallest number of moles you get 5) If need be multiple the subscript decimal given to make the subscript a whole number
Significant Figure Rules
1. non-zeros are always significant; 2. zeros between two other sig figs are significant; 3. all final zeros after the decimal point are significant; 4. zeros used solely for spacing the decimal point are not significant unless a decimal point is present
Integer to multiply by when you get anything .50
2
boiling point
212 fahrenheit, 100 celsius, 373.15 k
Integer to multiply by when you get anything .33
3
Integer to multiply by when you get anything .66
3
freezing point
32 degrees Fahrenheit, 0 degrees Celsius, 273.15 k
Integer to multiply by when you get anything .25
4
Integer to multiply by when you get anything .75
4
Integer to multiply by when you get anything .20
5
Integer to multiply by when you get anything .40
5
Integer to multiply by when you get anything .80
5
solute
A substance that is dissolved in a solution.
Fahrenheit formula
F=1.8C+32
Kelvin formula
K=C+273.15
Atomic mass
The average mass of all the isotopes of an element
Anion
an ion with a negative charge
Cation
an ion with a positive charge
Finding molarity when given moles and liters
divide moles/volume
Neutrons
mass number - protons
Atomic number
mass number- neutrons
Percent composition formula
mass of element/mass of compound x 100
Density
mass/volume
Molarity
moles of solute/liters of solution
mass number
protons + neutrons
Distance/time
speed
Converting from grams to atoms
step 1) convert from grams to moles my multiplying given element grams times 1 over molar mass step 2) multiply the answer you got in moles by 6.022*10^23 atoms/ 1 mole
Grams to moles formula
step 1) find molar mass of element step 2) divide g by 1 mole over molar mass
Converting from molecules to moles
step 1) multiply given moles of element times 6.022*10^23/1mole
Converting from moles to atoms
step 1) use avogadro's number step 2) multiply the given moles times 6.022*10^23 atoms over 1 mole or vice versa
Solvent
the substance in which the solute dissolves
Molecular and Empirical Formula
when given the molecular formula simplify the subscripts to get the empirical formula. if it can't be simplified it remains the same
Protons are the same as electrons except in what case
when you are given a cation or anion
If you multiply an integer by one decimal subscript in a compound
you have to multiply it times the rest of the whole number subscripts
Finding molarity when given grams of compound and ml
1) Convert grams to moles 2) Convert ml to liters 3) divide moles by the given L
Finding volume when given molarity and moles
1) Divide moles of compound/ Given molarity
finding the amu when given two isotope masses and abundances
1) convert the abundances to decimals Ex. if youre given 50.69% it will turn to 0.5069 2) multiply the decimal abundances times the mass of the isotope for each isotope given in the problem 3) add all the answers together
Molarity to Volume
1) find the molar mass of the given compound 2) convert grams to moles by multiplying the given grams by 1 mole over your compound molar mass 3) multiply the moles you got by 1 liter over the molarity given in the problem and you will get your final answer in liters
