Quick chem question about mole conversions. Easy 10 points!?

1) The other person has it wrong. One molecule of oxygen gas is two atoms of oxygen (it's O2, remember?). So, what you want to do is:

3.5moles O2 = 7moles oxygen atoms.

7mole * 6.02atoms/mol = 42.14 * 10^23 atoms = 4.214 * 10^24 atoms

2) Assuming this is an ideal gas at 273K and 1atm:

Each mole of gas takes up 22.4L.

22.4L/mol * 3.5 mol = 74.8L

3) Remember that 1 mole of a certain molecule has the mass in grams of that molecule's molecular weight.

Water is H2O - two molecules hydrogen, one molecule oxygen.

Molecular weight of water is 1+1+16 = 18

Therefore, each mole of water is 18 grams.

18g/mol * 3.5mol = 63grams

4) So, an empirical formula is a bit like a reduced fraction. Instead of saying 4/8, they say 1/2. But good to know is that if you have a molecular weight, and the empirical formula, you can easily figure out the molecular formula. The molecular weight will always be a multiple of the empirical formula's weight. Once you have that, multiply all the subunits by that number.

BNH2 has a weight of: 10.8+14+1+1 = 26.8

80.50 / 26.8 = 3.003

So, there you have it: B3 N3 H6

5) This is also pretty simple once you get the steps down.

Just divide each of those percentages by the atomic mass of each element:

C: 63.15 / 12 = about 5

O: 31.55 / 16 = 1.97 = about 2

H: 5.3 / 1 = about 5

If it doesn't come out to near whole numbers, multiply by a common number to get them there.

Empirical Formula: C5 O2 H5

6) Hmmm... This isn't really a complete question. How much silver carbonate do you have? Each Ag2CO3 has 2 Ag+ ions. So whatever the number of moles of the Ag2CO3, just multiply by 2 and you'll have the number of Ag+ ions.

Hope that helps :]

a million mm x 6.02 x 10^23 = 6.02 x 10^23 mm 6.02 x 10^23 mm x (a million m / one thousand mm) x (39.37 in / a million m) x (a million ft / 12 in) = a million.ninety 8 x 10^21 ft that's an similar as a million.ninety 8 trillion billion ft. a million.ninety 8 x 10^21 ft x (a million mi / 5280 ft) = 3.seventy 4 x 10^17 miles that's an similar as 374 billion million miles!

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yea that answer is correct because you must remember one mole of oxygen has 6.023x10^23 atoms and just multiply that by the 3.5

2) 3.5x22.4= 78.4L

3)3.5x16.0= 56

4)B3N3H6