Based on the graph, which of these statements is most likely correct about the periods 1800 to 1850 and 1900 to 1950?
select one:
a. there was decrease in global temperatures.
b. there was increase in global temperatures.
c. there was no significant change in solar activity.
d. there was no significant change in global climate.

Based on the graph, the statement that is most likely correct about the periods 1800 to 1850 and 1900 to 1950 is that there was decrease in global temperatures. The answer is letter B. The rest of the choices does not fit tot the description of the graph.

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