All of these EXCEPT helium in a balloon
Answer:
The correct answer is option D, that is, the ions are now combining to reduce their concentrations.
Explanation:
On the basis of the chemical equation:
PbCl₂ (s) ⇒ Pb²⁺ (aq) + 2Cl⁻ (aq)
It is mentioned that the value of Ksp is 1.8 × 10⁻²
As the solubility product is very less or negligible for this reaction that signifies that the ions produced are getting combined, resulting in the reduction of the concentration of the ions and enhancing the formation of the solid lead chloride. Therefore, they associate together to produce solid lead chloride.
Following reaction occurs in the given electrochemical system:

→ Fe +

Thus, under standard conditions
E(0) = E(0) Fe2+/Fe - E(0) Zn2+/Zn
where,

= standard reduction potential of Fe2+/Fe = -0.44 v

= standard reduction potential of Zn2+/Zn = -0.763 v
E(0) = 0.323 v
now, we know that, ΔG(0) =-nFE(0) ............... (1)
Also, Δ

On equating and rearranging equation 1 and 2, we get
K = exp(

)= exp (

) = 8.46 x
I think i found your answers