(20 points) In the morning, you decide to make toasted bacon, lettuce, and tomato sandwich. Observe what happens in each stage of making the sandwich. Which parts involve only chemical changes happening? I. The first thing you do is cut two slices of bread.
II. Then you put the slices in the toaster to cook. When the toaster is done, it pops the III. warm brown toast. You cook the bacon in a frying pan you put bacon, lettuce, and tomato on the bread, trimming the sides.
IV. You can smell the old bread in the garbage going moldy.

Steps I and II
Steps II and III
Steps II and IV
Steps III and IV

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

- decrease the number of plants and animals living in the water.

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