Posted by Gweedo8 on .
1. Tin and oxygen gas are reacted together to form Tin (IV) oxide, a solid. If a piece of tin foil, 8.25cm x 21.5cm x 0.60mm (density = 7.28g/cm3) is exposed to oxygen and all the tin reacts, what is the mass of the oxidized tin foil? (98.4g)
I am so confused on this problem the answer is 98.4 but can anyone show me how to get to that answer??????

Chemistry Stoichiometry 
SraJMcGin,
You might like the following for reference:
http://www.google.com/search?q=Chemistry++Stoichiometry+Tutorial&ie=utf8&oe=utf8&aq=t&rls=org.mozilla:enUS:official&client=firefoxa
Sra 
Chemistry Stoichiometry 
DrBob222,
Step 1. Write and balance the equation.
Sn + O2 ==> SnO2
Step 2. How much Sn do you have? You can find the volume (length x width x thickness but change the thickness of 0.60 mm tp 0.060 cm so that all of the units will be the same). Now you know
mass = volume x density. You now have the density and the volume in cm^3 so you can calculate the mass.
Step 3. Convert mass to moles. # moles Sn = grams Sn/molar mass Sn.
Step 4. Using the coefficients in the balanced equation, convert moles Sn to moles SnO2.
Step 5. Now convert moles SnO2 to grams SnO2. grams SnO2 = moles SnO2 x molar mass SnO2.
I didn't do the math but if you don't get the answer, either the answer is wrong or you slipped up somewhere. Post your work if that happens and I'll find the error. Good luck.