Select the correct answer.
why does every chemical reaction require a certain amount of activation energy?
o a
energy is released when the reactants begin to react.
o b. energy lost to the environment during the reaction must be replaced.
oc forming the activated complex requires energy.
od. the products have more potential energy than the activated complex.
o e.
the reactants have less potential energy than the products.

The first one

Explanation:

Out of those I'd say the first ones the most right, chemical bonds have to be broken to start a chemical reaction which is exothermic and does release energy.

So yea the top one I reckon.

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

answer

the ions in solute supperate from eachouthere