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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: zainriaz on June 05, 2010, 01:09:08 PM

Title: finding mole and name of elements
Post by: zainriaz on June 05, 2010, 01:09:08 PM
1)a sample of 0.6 moles of a metal M reacts completely with excess of flourine to form 46.8 gms of MF2.
a)how many moles of F are present in the sample of MF2 that forms?
b)which element is represented by the symbol M?


2. Relevant equations
NO. OF MOLES=given mass/molar mass

Relevant equations
NO. OF MOLES=given mass/molar mass


3. The attempt at a solution
molesof element M:moles of compound formed MF2
1 : 1
0.6 : 0.6
1 mole of MF2 contains 2 moles of F
0.6 MOLES WOULD CONTAIN=0.6*2=1.2

now i dnt no how can i find which element it is
Title: Re: finding mole and name of elements
Post by: Schrödinger on June 05, 2010, 01:41:18 PM
1.2 moles of Fluorine is correct. Now...what is the molar mass of fluorine, and how would you use it, given the molar mass of the compound?
Title: Re: finding mole and name of elements
Post by: aberneth on June 06, 2010, 02:23:19 PM
If you have formed .6mol of product, which includes 1.2 mol of ATOMIC fluorine, and fluorine has an atomic mass of 18g/mol, how many grams of fluorine are present in the product? Since you have 46.8 grams TOTAL of the product, how many grams of that is constituted by the metal? You know that you used 0.6 moles of metal M in the product, so once you know how many grams of it you have, you can find its molar mass.