The balanced chemical reaction is written as:
4Al + 3O2 = 2Al2O3
To determine the mass of oxygen gas that would react with the given amount of aluminum metal, we use the initial amount and relate this amount to the ratio of the substances from the chemical reaction. We do as follows:
moles Al = 16.4 g ( 1 mol / 26.98 g ) = 0.61 mol Al
moles O2 = 0.61 mol Al ( 3 mol O2 / 4 mol Al ) = 0.46 mol O2
mass O2 = 0.46 mol O2 ( 32.0 g / mol ) = 14.59 g O2
Therefore, to completely react 16.4 grams of aluminum metal we need a minimum of 14.59 grams of oxygen gas.
Answer:
-2092 kJ
Explanation:
Let's consider the chemical reaction that causes chromium to corrode in air.
4 Cr + 3 O₂ → 2 Cr₂O₃
We can calculate the standard Gibbs free energy (ΔG°) using the following expression.
ΔG° = ΔH° - T × ΔS°
where,
- ΔH°: standard enthalpy of the reaction
- ΔS°: standard entropy of the reaction
ΔG° = -2256 kJ - 298 K × (-0.5491 kJ/K)
ΔG° = -2092 kJ

given E = 9.4145E-25
h = 6.626E-34
c = 2.998E8
sub values into the equation above, and solve for wavelength.
You will get 0.211m