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Number of atoms in mol vs gr

  • Thread starter omni
  • Start date
  • #1
192
1
1) where i got more atoms in 20 gr H2SO3 or in 20 mol of HCl ?

2) tell me if i Right: the mass (in gr) of 100 Molecules Of SO2(g)

is: the mass of O2=31.998, the mass of S=32.065.

so Together the mass is about 31.998+32.065*100=6406.3 but i don't sure how to Change it to (gr) unit.


thanks.
 

Answers and Replies

  • #2
445
5
1) where i got more atoms in 20 gr H2SO3 or in 20 mol of HCl ?

2) tell me if i Right: the mass (in gr) of 100 Molecules Of SO2(g)

is: the mass of O2=31.998, the mass of S=32.065.

so Together the mass is about 31.998+32.065*100=6406.3 but i don't sure how to Change it to (gr) unit.


thanks.
What is the definition of 1 mol? Do you mean grains of sulfurous acid, or grams?
 
  • #3
5
0
Remember that the molecular masses you listed are in units of g/mol (grams per mole), where one mole is one Avogadro's number of molecules (1 mol = 6.022 x 10^23 molecules). So 100 molecules is a small fraction of a mole while 100 g could be a multiple or fraction (depending on the molecular mass) of a mole.
 
  • #4
192
1
well the definition of 1 mol i mean grams (g/mol)

and yes i listed the units of g/mol.
i still not Understand exactly how to find the answers.
 
  • #5
397
21
You seem to have some things mixed up and I'm not exactly sure what you are trying to do with your procedure (why are you trying to figure out the mass of 100 molecules of anything?).

A few hints/questions to help you on your way.

1. What does one mole of something represent?
(Hint: Its like saying a dozen of something. Except instead of a dozen being 12 of something, what does a mole stand for?)

2.
a. How many molecules of HCl do you have in 1 mole of HCl?
b. How many hydrogen's and how many chlorine's do you have in 1 mol of HCl?
c. Since you have 20 mols of HCl, how many H's and how many Cl's do you have?

3. Do you know how to convert mass to moles? (Hint: The molar mass is important.)

4.
a. How many moles of H2SO3?
b. How many atoms of H, S and O do you have then?
 
  • #6
192
1
1) well in 20 mol of HCl i got 120.4x10^23 atoms, Can be? (i did 20x6.02x10^23)

2) H2SO4= molar mass 98.079 g/mol and in the Question they ask me about how many atoms i got in 20 gr. so sure in 20gr i got less then 1 mol of H2SO4 cuz in 1 mol of H2SO4 i got 98.079 gr yes?
 
  • #7
192
1
ok i found the answer thanks all for help:)
 

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