how to find a molar mass?

Question

anonymous · Answer

2. Find the mass of each of the compounds by multiplying the percentage composition times the total mass of the sample. Convert the mass to moles by dividing by the molar mass of the compound.
percentage = 99.681
mass sample = 10 grams
so 99.681x10=996.81 then what do i do?

anonymous · Answer

bacically take the formula wieight of the compund and multiply by the number of moles you want

anonymous · Answer

how do i no what moles im suppose to get or it doesnt matter?

anonymous · Answer

well, for example if i wanted 0.1 moles of NaCL, then i would find the formula weight of the compound and multiply it by 0.1

anonymous · Answer

that would give you 0.1 moles of NaCL

anonymous · Answer

what happens if its a unknown compound?

anonymous · Answer

are you given the formula weight of the compund or at lest the elements ?

anonymous · Answer

it gave me these and told me to add them and said it would be less then 100 and i had to find the difference. 
Percentage composition:
Water: 54.00%
Ammonia: 8.500%
Methane: 32.00%
Hydrogen: 15.78%
Carbon: 25.68%
Nitrogen: 7.981%
Oxygen: 50.24%

anonymous · Answer

Conider this, i believe it has the answers your looking for : http://go.hrw.com/resources/go_sc/mc/HUGPS062.PDF

anonymous · Answer

thank you

anonymous · Answer

wont let me open it

anonymous · Answer

says problem loading page

anonymous · Answer

man, i just opened it, and now it wont let me open.

anonymous · Answer

dang =/ well ill try again in few mins then thank you again