How many grams of co are needed with an excess of fe2o3 to produce 27.9 g fe? show work. fe2o3(s)+3co(> 2fe(s)+3co2(g)

21.0 g.

Explanation:

Firstly, It is considered as a stichiometry problem.From the balanced equation: Fe₂O₃ + 3CO → 2Fe + 3CO₂.It is clear that the stichiometry shows that 1.0 moles of Fe₂O3 reacts with 3.0 moles of CO to give 2.0 moles of Fe and 3.0 moles of CO₂.We must convert the grams of Fe (27.9 g) to moles (n = mass/Atomic mass).n = (27.9 g) / (55.845 g/mole) = 0.499 ≅ 0.50 moles.Now, we can get the number of moles of CO that is needed to produce 0.50 moles of Fe.Using cross multiplication:3.0 moles of CO → 2.0 moles of Fe, from the stichiometry of the balanced equation.??? moles of CO → 0.50 moles of FeThe number of moles of CO that will produce 0.50 moles of Fe (27.9 g) is (3.0 x 0.50 / 2.0) = 0.75 moles.Finally, we should convert the number of moles of CO into grams (n = mass/molar mass).Molar mass of CO = 28.01 g/mole.mass = n x molar mass = (0.75 x 28.01) = 21.0 g.

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assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

explanation

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.