Answer:
Option (E) is correct
Explanation:
Solubility equilibrium of 
is given as follows-
Hence, if solubility of is S (M) then-
![[Pb^{2+}]=S(M)](https://tex.z-dn.net/?f=%5BPb%5E%7B2%2B%7D%5D%3DS%28M%29)
and ![[IO_{3}^{-}]=2S(M)](https://tex.z-dn.net/?f=%5BIO_%7B3%7D%5E%7B-%7D%5D%3D2S%28M%29)
Where species under third bracket represent equilibrium concentrations
So, solubility product of , ![K_{sp}=[Pb^{2+}][IO_{3}^{-}]^{2}](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BPb%5E%7B2%2B%7D%5D%5BIO_%7B3%7D%5E%7B-%7D%5D%5E%7B2%7D)
Here, ![[Pb^{2+}]=S(M)=5.0\times 10^{-5}M](https://tex.z-dn.net/?f=%5BPb%5E%7B2%2B%7D%5D%3DS%28M%29%3D5.0%5Ctimes%2010%5E%7B-5%7DM)
So, ![[IO_{3}^{-}]=2S(M)=(2\times 5.0\times 10^{-5})M=1.0\times 10^{-4}M](https://tex.z-dn.net/?f=%5BIO_%7B3%7D%5E%7B-%7D%5D%3D2S%28M%29%3D%282%5Ctimes%205.0%5Ctimes%2010%5E%7B-5%7D%29M%3D1.0%5Ctimes%2010%5E%7B-4%7DM)
So, 
Hence option (E) is correct
Answer:
The resulting solution is basic.
Explanation:
The reaction that takes place is:
First we <u>calculate the added moles of HNO₃ and KOH</u>:
- HNO₃ ⇒ 12.5 mL * 0.280 M = 3.5 mmol HNO₃
- KOH ⇒ 5.0 mL * 0.920 M = 4.6 mmol KOH
As <em>there are more KOH moles than HNO₃,</em> the resulting solution is basic.
Answer: [D]: "They are not part of the rock cycle." .
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