Fe3O4 + 4 C right arrow 3 Fe + 4 CO

What is the maximum mass of Fe which could be made from 115.0 g Fe3O4 of and 24.00 g C?

 

 

 

 

 

 

 

 

 

 

 

 

 

The trick here is to find the maximum amount of iron which could be made from each reactant. The lesser amount will then be the max possible:

C: (3 mol Fe/ 4 mol C)(24.00 g C/ 12.01 g C/mol C) = 1.499 mole

 

 

 

 

Fe3O4: (3 mol Fe/ mol Fe3O4)(115.0 gFe3O4/231.6 g Fe3O4/mol Fe3O4) = 1.490 mole

 

 

 

 

 

 

C: (3 mol Fe/ 4 mol C)(24.00 g C/ 12.01 g C/mol C) = 1.499 mole

Fe3O4: (3 mol Fe/ mol Fe3O4)(115.0 gFe3O4/231.6 g Fe3O4/mol Fe3O4) = 1.490 mole

\ Fe3O4 limits, can only make 1.490- moles.

 

 

 

 

 

 

 

So mass is then= (1.490 moles) (55.85 g/mole) = 83.22 g Fe

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Solubility Rules

It is useful to remember some simple "rules" (really more like guidelines) to help in predicting reactions. For common compounds such as we see in general chemistry we can use the following rules:

  1. Nitrates (NO3-) are all soluble.
  2. Alkali metal (Li+, Na+, K+, Cs+, and Rb+) and ammonium (NH4+) salts are all soluble, with the exception of a few Lithium salts.
  3. Chloride, bromide, and iodide (Cl-, Br-, and I-) salts are generally soluble, except for the salts of silver, lead(II) and mercury(I) (Ag+, Pb2+ and Hg22+).
  4. Sulfates are soluble, except for the salts of barium {BaSO4}, lead(II) {PbSO4}, mercury(II) {HgSO4}, and calcium {CaSO4}.
  5. Most hydroxides are only slightly soluble (but see rule 2).
  6. Sulfides (S2-), carbonates (CO32-), phosphates (PO43-), and chromates (CrO42-) are only slightly soluble (but see rule 2).

Examples using these rules may be found in the Module

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Most Reactive

H2 released in cold water

K

   

Ba

   

Sr

   

Ca

   

Na

   
H2 released in steam

Mg

   

Al

   

Mn

   

Zn

   

Cr

   

Fe

   

Cd

   
H2 released in acids

Co

   

Ni

   

Sn

   

Pb

   
 

H2

   

H2 not released

Sb

   

Bi

   

Cu

   

Ag

   

Hg

   

Pd

   

Pt

   

Au

   

Least Reactive

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

© R A Paselk

Last modified 24 September 2009