How do you balance Al + F_2 -> AlF_3Al+F2AlF3?

2 Answers
Feb 28, 2016

Al + F_2 rarrAlF_3Al+F2AlF3
here F is unbalanced : on right hand side(product side) there are 3 F and on the left hand side there is 2F

use the L.C.M of the two numbers to balance on both sides
here L.C.M of (2,3)=6
so we try to get six F on both sides

Al + 3F_2 rarr 2AlF_3Al+3F22AlF3
now we need to balance Al
2Al +3F_2 rarr2AlF_32Al+3F22AlF3

Feb 28, 2016

You balance it stoichiometrically: GARBAGE IN MUST EQUAL GARBAGE OUT.

Explanation:

A chemical reaction ALWAYS CONSERVES MASS AND CHARGE:

2Al(s) + 3F_2(g) rarr 2AlF_3(s)2Al(s)+3F2(g)2AlF3(s).

Is mass conserved in this representation? How? If you have to do calculations with this formula, to make it a little easier on yourself you could write:

Al(s) + 3/2F_2(g) rarr AlF_3(s)Al(s)+32F2(g)AlF3(s)

What does 1/2F_2(g)12F2(g) represent in "grams"grams?