things to remember

Question 1

x

Answer 1

mass of compound/ mass of empirical formula

Question 2

moles

Answer 2

n = m (mass)/M (Molar Mass)

Question 3

moles (from atoms)

Answer 3

n = N (particles)/ Na (Avogadro)`

Question 4

To find mass of excess reactant unreacted

Answer 4

calculate moles reacted then subtract total amount by the amount reacted. times this by M

Question 5

molecular vs. empirical

Answer 5

molecular: how many atoms of each element in a compound
empirical: the simplest and most reduced RATIO of atoms in a compound

Question 6

steps for hydrate given a percentage of one Element

Answer 6

1) do the ratio (percent given/mass of element times ()percent x/ ()mass of element.). repeat for number of elements in compound
2) add up percentages, 100-x = percent hydrate
3) assume 100g, find moles, divide by smallest= EF

Question 7

percentage yield (What is it, find moles unreacted)

Answer 7

is also a ratio
write down everything. to find amount unreacted, find reacted amount (()mol times mol/()mol of other reactant ) then subtract total amount - reacted to get mol unreacted. times by M to get moles excess unreacted

Question 8

why do you divide by lowest number of moles in EF?

Answer 8

divide because you want to find out how many particles are bonded to each particle of the lowest # of moles

Question 9

what does chemical formula give you

Answer 9

relative amounts of particles/moles. balanced eqn is needed because it shows the amount of moles in relation to different products

Question 10

how to go from atoms to mass and back

Answer 10

Order: # of atoms- # of molecular - Moles - mass
EQN: (chemical formula, avogadro, Molar mass)

Question 11

!!! Molar mass of a compound

Answer 11

is not the molar mass of the EF! It is molar mass of the MF!