Question

The solubility product of sparingly soluble salt BA is \(4\times 10^{-13}\). Calculate the \([\text{A}^-]\) if \([\text{B}^+]\) is \(1\times 10^{-6} \text{M}\).

• A. \(2\times 10^{-7} \text{M}\)
• B. \(3\times 10^{-7} \text{M}\)
• C. \(4\times 10^{-7} \text{M}\)
• D. \(5\times 10^{-7} \text{M}\)

Hint:

For BA, Ksp is the product of the two ion concentrations.

Answer 1

The Correct Option is C

Step 1: Rearrange
With $K_{sp} = [B^+][A^-]$, dividing both sides by $[B^+]$ gives $[A^-]$.

Step 2: Calculate
$[A^-] = 4\times 10^{-13} \div 10^{-6} = 4\times 10^{-7}$ M, which is option (C).

Final Answer:
A- is 4 x 10^-7 M. \[ \boxed{\text{(C)}\ 4\times 10^{-7}\ \text{M}} \]