The reaction is:
6 Cr²⁺ + Cr₂O₇²⁻ + 14 H⁺ → 8 Cr³⁺ + 7 H₂O
E₀ = 1.33 - (-0.5) = 1.83 V
ΔG = - n f E₀
= - 6 * 96485 * 1.83
= - 1059405.3 J / mol
= - 1059.4 kJ / mol
Answer:
Ka = 1.39x10⁻⁶
Explanation:
A monoprotic acid, HX, will be in equilibrium in an aqueous medium such as:
HX(aq) ⇄ H⁺(aq) + X⁻(aq)
<em>Where Ka is:</em>
Ka = [H⁺] [X⁻] / [HX]
<em>Where [] is the molar concentration in equilibrium of each specie.
</em>
The equilibrium is reached when some HX reacts producing H+ and X-, that is:
[HX] = 1.64M - X
[H⁺] = X
[X⁻] = X
As pH is 2.82 = -log [H⁺]:
[H⁺] = 1.51x10⁻³M:
[HX] = 1.64M - 1.51x10⁻³M = 1.638M
[H⁺] = 1.51x10⁻³M
[X⁻] = 1.51x10⁻³M
And Ka is:
Ka = [1.51x10⁻³M] [1.51x10⁻³M] / [1.638M]
<h3>Ka = 1.39x10⁻⁶</h3>
Open system is a system in which mass or energy can be lost to or gained from the environment. In this case, water and power come from external sources best explains why a washing machine would be considered an open system.
