Question

Help Pleaseeeee!!!!!!! I will give medals and become fan!

If a sample of barium contains 2.3 x 10^23 atoms of barium, how many grams of barium are in the sample

Answer 1

oh and there is options for answers give me a sec to give them

Answer 2

So you know the number of atoms is the Avogadro number times the number of moles. And you know you can get the mass of material from the number of moles and relative molecular/atomic mass. Right?

Answer 3

No i didn't, i am okay at chemistry, the only part that gets me is the math. I just need help working through this problem and a couple others, but you dont have to help with the others and here are the options

a: 0.38g
b: 2.62g
c: 52.4g
d: 359.5g

Answer 4

As I said, since atomic number is Avogadro number times number of moles, you divide it by A number to get # of moles. And then you multiply it by the RMM/RAM to get mass again.

Answer 5

This might help http://saxonylutheranlovechemistry.wikispaces.com/file/view/Converting%20between%20mols%20to%20grams%20and%20atoms.png/359038475/323x304/Converting%20between%20mols%20to%20grams%20and%20atoms.png

Answer 6

Or this http://cbse.meritnation.com/img/editlive_lp/77/2012_06_07_10_29_14/Gr11_Ch1.png

Answer 7

ok thank you i will try but i don't know h0w good i will be

Answer 8

whoever looks at this i still need help!

Answer 9

I think the last picture I gave you says it all. It has all the steps you need.

Answer 10

I fell very stupid because I still dont understand

Answer 11

Trust me, the math is not that hard. If you go on, the math gets far worse. But anyways, start with what you're given: \(\sf \color{red}{2.3 \times 10^{23} ~atoms}\). Make sure that you note your units!

Answer 12

Now, use avogadro's number: \(\sf \color{orange}{6.022 \times 10^{23}} \frac{mol}{atom}\) to divide and cancel out the units of atom that you have.

Answer 13

You have the number of atoms... divide that by a mole (6.02x10^23) to see how many moles, that's your first step... knowing the number of moles.



THEN multiply the number of moles, by the atomic weight of barium (look at barium on a periodic table)

Answer 14

You will be left with a small number. Next, look at your periodic table OR visit this website: http://www.ptable.com/ and look the element Ba (barium). multiply by the given mass on the p-table. Since you know that molar mass on the periodic table is in units of: \(\sf \color{blue}{\frac{grams}{mol}}\)

Answer 15

You're plan should be: \(\sf \color{green}{atoms \rightarrow mol~of~Ba \rightarrow grams~of~Ba}\)

Answer 16

^yep. Basically you always want to get moles first, and use that to get whatever else you need (litres of gas, mass in grams, etc)

Answer 17

thanks guys my internet crashed sorry....