Posted by Kaye on Tuesday, January 18, 2011 at 6:05pm.
The rusting of iron is represented by the equation 4Fe +3O2 > 2Fe2O3. If you have a 1.50mol sample of iron, how many moles of Fe2O3 will there be after the iron has rusted completely?
a. 0.50 mol
b. 0.75 mol
c. 1.0 mol
d. 1.50 mol
e. 2.0 mol
> I got "b" using ratios..is that correct?

Chemistry e  DrBob222, Tuesday, January 18, 2011 at 10:28pm
Look at the equation.
The equation tells us that 4 moles Fe will produce 1 moles of the oxide; therefore, 1.5 mol will produce 1/2 that or 0.75 mol which is answer b. 
Chemistry e  Kaye, Tuesday, January 18, 2011 at 11:04pm
Thank you very much!
I tried answering this one but I am getting answers that are not in the 4 choices given...Help?
8. The balanced equation P4 (s) + 6H2 (g) > 4PH3 tells us that 2 mol H2
a. reacts with 1 mol 4
b. produces 4 mol PH3
c. cannot react with phosphorus
d. produces 2 mol PH3
e. reacts with 2 mol P4