The Lewis structure the student drew is incorrect. The total number of electrons in bonds and lone pairs is equal to the total number of valence electrons available, then a valid Lewis structure is produced.
The correct structure is the following:
The structure that was drawn by the student was incorrect because the total number of electrons around Oxygen were incorrect, there were 6 instead of 8, which was against the octet rule. The correct structure should have 8 electrons around each atom.
The symbols indicate the physical state of each reactant
Answer:
Molarity of 40 ml of NaoH is 0.3125 mL
Explanation:
As we know
Molarity of acid * volume of acid = molarity of base * volume of base
Substituting the given values, we get

Molarity of 40 ml of NaoH is 0.3125 mL
Answer:
Number of moles of Fe = 10 mol
Number of moles of CO₂ = 15 mol
Explanation:
Given data:
Number of moles of iron oxide = 5 mol
Number of moles of carbon monoxide = 25 mol
Number of moles of product = ?
Solution:
Fe₂O₃ + 3CO → 2Fe + 3CO₂
Now we will compare the moles of reactant with product.
Fe₂O₃ : Fe
1 : 2
5 : 2×5 = 10 mol
Fe₂O₃ : CO₂
1 : 3
5 : 3×5 = 15 mol
CO : Fe
3 : 2
25 : 2/3×25 = 16.7 mol
CO : CO₂
3 : 3
25 : 25
Less number of moles of Fe and CO₂ are formed by iron oxide thus it will act as limiting reactant while CO is inn excess.