One equation for the number of moles in a compound:
[tex]number.of.moles = \frac{mass}{mr}[/tex]
(note: Mr is the combined molecular mass of the compound.)
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On the periodic table:
Lithium (Li) has a molecular mass of around 7
Fluorine (F) has a molecular mass of around 19.
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So the total Mr of Lithium Fluoride (LiF) is:
7 + 19 = 26
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Now to work out the number of moles, we just divide the mass (in grams) of the compound by the Mr of the compound (as in the formula):
[tex]number.of.moles = \frac{mass}{mr}[/tex]
[tex]number.of.moles = \frac{110}{26}[/tex]
[tex]number.of.moles = 4.2[/tex]
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Answer:
A) 4.2
