## anonymous one year ago The 64.8-g sample of the compound X2O5 contains 48.0 g of oxygen atoms. What is the molar mass of element X?

1. Rushwr

What do u think ?

2. anonymous

i don't know i tried 5 times & continue to get the wrong answer

3. Rushwr

Mass of X2 = 64.8g - 48g right?

4. Rushwr

So the mass of X2 is 16.8g

5. Rushwr

Now we have to find the moles of oxygen

6. Rushwr

$moles = \frac{ mass }{ molar mass} = \frac{ 48 }{ 16 } = 3moles$

7. Rushwr

are u there?

8. anonymous

yes

9. Rushwr

$\frac{ 2 }{ 5 } = \frac{ xmoles }{ 3 }$ $x moles = 1.2$ Now we know the moles of X2

10. anonymous

okay..

11. Rushwr

we know the moles and the mass we just have to find the molar mass by using molar mass = mass/moles

12. Rushwr

$molar mass = \frac{ 16.8 }{ 1.2 } = 14gmol ^{-1}$

13. anonymous

YES thank you

14. Rushwr

Welcome !!!!!!!!! DId u get it ? :)

15. anonymous

yes!