<span>In the distant future, earth was no longer habitable by humans due to extreme pollution and excessive waste. Humans were not allowed to go back to earth due to the severity of the planet's condition and they dwell in space for hundreds of years while WALL-E, short for Waste Allocation Load Lifter Earth-class, was the only robot left to clean the planet, little by little.</span>
When an electron moves from a higher to a lower energy level, energy is released (often as light).
Chemical reaction: PCl₅ → PCl₃ + Cl₂.
n(PCl₅) = 0,366 mol.
V(PCl₅) = 4,45 L.
c(PCl₅) = n(PCl₅) ÷ V(PCl₅).
c(PCl₅) = 0,366 mol ÷ 4,45 L.
c(PCl₅) = 0,082 mol/L.
Kc = 1,80.
[PCl₃] = [Cl₂] = x.
Kc = [PCl₃] · [Cl₂] ÷ [PCl₅].
1,80 = x² ÷ (0,082 mol/L - x).
Solve quadratic eqaution: x = [PCl₃] = 0,078 mol/L.
[PCl₅] = 0,082 mol/L - 0,078 mol/L.
[PCl₅] = 0,004 mol/L.
