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Calculate the volume of water required t...

Calculate the volume of water required to dissolve`0.1g` lead (II) chloride to get a saturaed solution `(K_(sp)` of `PbCI_(2) = 3.2 xx 10^(-8)`, atomic mass of `Pb = 207 u)`. Multiply your answer with 10 to get answer.

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To calculate the volume of water required to dissolve 0.1 g of lead (II) chloride (PbCl2) to get a saturated solution, follow these steps: ### Step 1: Write the dissociation equation Lead (II) chloride dissociates in water as follows: \[ \text{PbCl}_2 (s) \rightleftharpoons \text{Pb}^{2+} (aq) + 2 \text{Cl}^- (aq) \] ### Step 2: Define solubility (S) Let the solubility of PbCl2 in water be \( S \) mol/L. Therefore, the concentration of lead ions (\( \text{Pb}^{2+} \)) will be \( S \) and the concentration of chloride ions (\( \text{Cl}^- \)) will be \( 2S \). ### Step 3: Write the expression for Ksp The solubility product constant (\( K_{sp} \)) for PbCl2 can be expressed as: \[ K_{sp} = [\text{Pb}^{2+}][\text{Cl}^-]^2 = S \cdot (2S)^2 = 4S^3 \] ### Step 4: Substitute the given Ksp value Given that \( K_{sp} = 3.2 \times 10^{-8} \): \[ 3.2 \times 10^{-8} = 4S^3 \] ### Step 5: Solve for S Rearranging the equation gives: \[ S^3 = \frac{3.2 \times 10^{-8}}{4} = 0.8 \times 10^{-8} = 8 \times 10^{-9} \] Now, take the cube root: \[ S = (8 \times 10^{-9})^{1/3} = 2 \times 10^{-3} \, \text{mol/L} \] ### Step 6: Calculate the number of moles of PbCl2 To find the number of moles of PbCl2 in 0.1 g, use the molar mass: - Molar mass of Pb = 207 g/mol - Molar mass of Cl = 35.5 g/mol - Molar mass of PbCl2 = 207 + (2 × 35.5) = 207 + 71 = 278 g/mol Now calculate the number of moles: \[ \text{Number of moles} = \frac{\text{mass}}{\text{molar mass}} = \frac{0.1 \, \text{g}}{278 \, \text{g/mol}} \approx 3.60 \times 10^{-4} \, \text{mol} \] ### Step 7: Calculate the volume of water required Using the molarity (S) we found earlier: \[ \text{Molarity} = \frac{\text{Number of moles}}{\text{Volume in L}} \] Rearranging gives: \[ \text{Volume in L} = \frac{\text{Number of moles}}{S} = \frac{3.60 \times 10^{-4} \, \text{mol}}{2 \times 10^{-3} \, \text{mol/L}} = 0.18 \, \text{L} \] ### Step 8: Convert volume to mL Since the question asks for the volume in mL, we convert: \[ 0.18 \, \text{L} = 180 \, \text{mL} \] ### Step 9: Multiply by 10 as per the question Finally, multiply the volume by 10: \[ 180 \times 10 = 1800 \] ### Final Answer The final answer is **1800**. ---
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