the compound tin(II)fluoride,or stannous fluoride,once was a common ingredient in toothpaste.It is produced according to the following reactions:

Sn(s)+2HF(g)->SnF2(s)+H2(g)
if 45.0 grams og HF react with Sn,how many grams of stannous fluoride are produced?

1 answer

Worked example of a simple stoichiometry problem.
http://www.jiskha.com/science/chemistry/stoichiometry.html