[dudebuddyguy]

How do I figure this stuff out?

5. How many moles are there in 2.9 x 10²³ molecules of carbon dioxide, CO2?

6. How many atoms are there in 0.349moles of Iron, Fe?

7. How many grams does 3.7 x 10²⁴ atoms of sodium weigh?

This stuff is really throwing me off. That, and I need to show my work to get full marks and my calculator keeps responding to 10²³ with 1e+23 and such which doesn't help me.

As for the Iron-related question, if this was asking me the mass of 0.349 moles of Iron, I'd just do 55.847 divided by 0.349 to get my answer....but it's asking about atoms. How the heck do you calculate atoms 

[kriggy]

Well this might be helpful to your problems
http://en.wikipedia.org/wiki/Avogadro_constant.
about the iron problem, how many atoms are in 1 mole?

[dudebuddyguy]

Well this might be helpful to your problems
http://en.wikipedia.org/wiki/Avogadro_constant.
about the iron problem, how many atoms are in 1 mole?

Yeah, so I read the Wikipedia article. Still confused as to how to properly calculate this stuff.

As for iron, I'm reading that there are 6.022 X 10²³ atoms....which means I'm back at where I started, completely confused again.

Do I just ignore the 10²³ and divide 6.022 by 0.349?

[eazye1334]

This stuff is really throwing me off. That, and I need to show my work to get full marks and my calculator keeps responding to 10²³ with 1e+23 and such which doesn't help me.

1e+23 is just the calculator shorthand for 10²³. They're the same thing according to the calculator.

[Borek]

Mole is just an overgrown dozen. If you have half a dozen of iron atoms, how many do you have? If you have half a mole of iron atoms, do the calculations exactly the same way, just the mole of iron atoms has 6.02×10²³ atoms, not 12.

[dudebuddyguy]

Mole is just an overgrown dozen. If you have half a dozen of iron atoms, how many do you have? If you have half a mole of iron atoms, do the calculations exactly the same way, just the mole of iron atoms has 6.02×10²³ atoms, not 12.

Ok, so I was right when I assumed this was a simple division problem?

Because one iron mole has 6.02 x 10²³ atoms. So .349 of a mole would obviously have less than half of 6.02

[Borek]

Half of a dozen is 0.5×12 - that's not a division.

iron mole has 6.02 x 10²³ atoms. So .349 of a mole would obviously have less than half of 6.02

Less than half of 6.02×10²³.

[dudebuddyguy]

Half of a dozen is 0.5×12 - that's not a division.

iron mole has 6.02 x 10²³ atoms. So .349 of a mole would obviously have less than half of 6.02

Less than half of 6.02×10²³.

So like, 3.01 x 10¹¹ (along those lines?)

[Borek]

Apparently part of your problem is simple math - you have no idea how to deal with the exponential part and what it means.

602 can be written as 6.02×100 = 6.02×10².

How much is half of that? Write it using all three methods. Does it require changing the exponent in 10², or is it enough to change the 6.02 part?