First we will calculate the number of moles of Iron:

, where n is the number of moles, m is the mass of iron in the reaction and M is the Atomic weight.

moles of Iron.
The same number of moles of Oxygen will take part in the reaction.
So

where 32 is the Atomical Weight of Oxygen (16 x 2).
=>

g
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Answer: p2 = 1.06p1
Explanation: pressure increases with temperature increase.
According to Gass law
P1/T1 = P2/T2
T1 = 20°c = 20 +273 = 293k
T2 = 40°c = 40 +373 = 313k
Therefore
P2 = P1T2/T1 = 313P2/293
P2 = 1.06P1
Answer:2
Explanation:
Ba(OH)2 contains two oxygen atoms
BaSO4 contains four oxygen atoms.
This means that barium sulphate contains two more oxygen atoms than barium hydroxide in its formula. This is clearly seen from the two formulae shown above.
Answer:
Gd → Gd⁺ + 1e⁻, Gd⁺ → Gd⁺² + 1e⁻, Gd⁺² → Gd⁺³ + 1e⁻
Explanation:
The ionization energy is the energy necessary to remove one electron of the atom, transforming it in a cation. The first ionization energy is the energy necessary to remove the first electron, the second energy, to remove the second electron, and then successively.
Thus, for gadolinium (Gd)
Fisrt ionization:
Gd → Gd⁺ + 1e⁻
Second ionization:
Gd⁺ → Gd⁺² + 1e⁻
Third ionization:
Gd⁺² → Gd⁺³ + 1e⁻