Gen Chem Question

[laurasmith]

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Does anybody know a short way to solve these problems?

1)What is the emperical formula for a compound with 20.8% Xe, 44.3% Pt and 25.9% F?

a) XePtF4
b)XePtF5
c)XePtF6
d)XePtF3


2) What volume of HCl was added if 20 ml of 1 M NaOh is titrated with 1M HCl to produce Ph=2?


Thanks

 

[jessUMD]

These values should add up to 100%... they only add to 91%. are you sure you copied the problem correctly?

 

[FreeTibet]

I took the second top score exam and i think i saw that problem in top score's second test but the numbers seemed to differ. Anyways i got that wrong too so if i did figure out how to do that i'll surely let u know.

 

[luder98]

Does anybody know a short way to solve these problems?

1)What is the emperical formula for a compound with 20.8% Xe, 44.3% Pt and 25.9% F?

a) XePtF4
b)XePtF5
c)XePtF6
d)XePtF3


2) What volume of HCl was added if 20 ml of 1 M NaOh is titrated with 1M HCl to produce Ph=2?


Thanks

First, they should add up to 100%. Anyway, this is how you do it...

Assume we have 100 g of the compound. You'll have:

20.8g Xe, 44.3g Pt and 25.9g F. Calculate the moles of each. Divide all three by the smallest. You'll get 1 for the smallest, round the other two. That will give you the formula.

2. Has been posted.

Good luck.