Given the equation: __fecl2 + __na2co3 → __feco3 + __nacl when the equation is correctly balanced using the smallest whole numbers, the coefficient of nacl is

2 will be the number

Explanation:

To balance a chemical reaction like this one, we have to know the priority order of balance.

In general, the priority order for balancing is:

Metals > Non metals > Hydrogen > Oxygen

Following this order, we can balance almost any chemical reaction we have:

Now, using this priority, let's balance the equation.

The metals here are Fe and Na, so let's check both of them in both sides of the reaction.

In the case of Fe, we have the same number of atoms in reactants (1) and in the product, so, in theory, we do not need to balance this metal.

In the case of Na, we can see that in reactants we have 2 atoms, but in the products we have 1, so we need to put a number 2 next to the Na in the product. It will keep like this: 2NaCl. This 2, also alter the number of Cl, but we will see that later. We have the metals balanced.

Let's see the non metals which are Carbon and chloride. In the case of C, we have in both sides the same number of C (1). In the case of Chloride, we also have the same number on both sides (2), because we put a 2 in products to balance the Sodium, and this balance the chloride too. So non metals are balanced.

We do not have hydrogens, so, let's see the oxygen. We have 3 in reactants and 3 in products, so they are already balanced, so we do not need to balance.

The balanced equation will be:

FeCl₂ + Na₂CO₃ > FeCO₃ + 2NaCl

Therefore the coefficient of NaCl is 2.

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g