Q: Given the solubility of AgCl at 25°C is 0.00019 g per 100 mL, what is the $$K_{ps}$$ value for AgCl? (Molar mass of AgCl = 143 g/mol)

$$K_{ps} = 1.8 \times 10$$^{-10}$$

Q: If the solubility of $$Ag_3PO_4 at 25$$°C is 0.20 mg per 100 mL, what is the $$K_{ps}$$ value? (Molar mass of $$Ag_3PO_4 = 419 g/$$mol)

$$K_{ps} = 1.4 \times 10$$^{-20}$$

Q: Calculate the minimum concentration of $$S^{2-}$$ required to initiate precipitation of FeS in a solution containing $$1.0 \times 10$$^{-4}$$ M Fe$$^{2+}$$, given K$$_{ps} = 5.0 \times $$10^{-18}.$$

$$[S$$^{2-}$$] = 5.0 \times 10$$^{-14}$$ M

Question 1

Which of the following best describes the solubility product constant ($$K_{ps}) $$for AgCl?

Accepted Answer

$$K_{ps} = [Ag^+] [Cl^-]$$

Question 2

Given the solubility of AgCl at 25°C is 0.00019 g per 100 mL, what is the $$K_{ps}$$ value for AgCl? (Molar mass of AgCl = 143 g/mol)

Accepted Answer

$$K_{ps} = 1.8 	imes 10$$^{-10}$$

Question 3

For the salt $$Ag_3PO_4$$, which of the following is the correct expression for its solubility product constant ($$K_{ps}$$)?

Accepted Answer

$$K_{ps} = [Ag^+]^3 [PO_4$^{3-}]$$

Question 4

If the solubility of $$Ag_3PO_4 at 25$$°C is 0.20 mg per 100 mL, what is the $$K_{ps}$$ value? (Molar mass of $$Ag_3PO_4 = 419 g/$$mol)

Accepted Answer

$$K_{ps} = 1.4 	imes 10$$^{-20}$$

Question 5

For $$CaF_2$$, if $$s is $$the molar solubility, which equation correctly relates $$K_{ps}$$ and $$s$$?

Accepted Answer

$$K_{ps} = 4s^3$

Question 6

A solution contains $$[Ba$$^{2+}$$] = 1.0 	imes 10$$^{-3}$$ M and $$[$$SO_4$$^{2-}] = 1.0 	imes $$10^{-4} M. If$$ $$K_{ps}$$ for $$BaSO_4 is$$ $$1.0 	imes 10$$^{-10}$$, will a precipitate form?

Accepted Answer

Yes, because $$PI \u003e K_{ps}$$

Question 7

Which of the following statements about the effect of a common ion on the solubility of AgCl is correct?

Accepted Answer

Adding $$Cl^-$$ decreases the solubility of AgCl

Question 8

Calculate the minimum concentration of $$S^{2-}$$ required to initiate precipitation of FeS in a solution containing $$1.0 	imes 10$$^{-4}$$ M Fe$$^{2+}$$, given K$$_{ps} = 5.0 	imes $$10^{-18}.$$

Accepted Answer

$$[S$$^{2-}$$] = 5.0 	imes 10$$^{-14}$$ M

Question 9

Which of the following will increase the solubility of a sparingly soluble salt in water?

Accepted Answer

Addition of a strong acid that reacts with one of the ions

Question 10

Given $$K_{ps}$$ for $$Ag_2CrO_4 is$$ $$1.3 	imes 10$$^{-12}$$, what is the molar solubility s$?

Accepted Answer

$$s = \sqrt{\frac{K_{ps}}{4}}$$

Question 11

If the ionic product ($$PI) of a $$solution is less than $$K_{ps}$$, what does this indicate?

Accepted Answer

The solution is unsaturated and no precipitate will form

Question 12

Which equation correctly expresses the ionic strength ($$I) of a $$solution containing $$[Na^+] = 0.2 M $$and $$[SO_4$^{2-}] = 0.1 M$$?

Accepted Answer

$$I = \frac{1}{2} \left( [Na^+](+1)^2$ + [SO_4$^{2-}](-2)^2$ \right)$$

Question 13

What is the effect of adding a non-common ion (e.g., $$KNO_3) to a $$solution containing AgCl?

Accepted Answer

It increases the solubility of AgCl due to the ion-diverse effect

Question 14

Which of the following is true regarding the calculation of $$K_{ps}$$ from solubility for $$BaSO_4$$?

Accepted Answer

$$K_{ps} = s^2$

Question 15

A solution contains $$0.01 M$$ $$KNO_3. $$How does this affect the solubility of AgCl compared to pure water?

Accepted Answer

The solubility of AgCl increases due to the ion-diverse effect

Question 16

Which factor does NOT affect the equilibrium of precipitation for sparingly soluble salts?

Accepted Answer

Addition of a non-reactive gas

Question 17

If the solubility of AgCl in water is $$1.34 	imes 10$$^{-5}$$ M, what is the solubility in a solution containing 0.01$ M $$KNO_3$$? (Assume the ion-diverse effect applies)

Accepted Answer

$$1.50 	imes 10$$^{-5}$$ M

Question 18

Which of the following is the correct general expression for the solubility product constant ($$K_{ps}) $$for a salt $$M_xA_y$$?

Accepted Answer

$$K_{ps} = [M$$^{y+}$$]^x [A$$^{x-}$$]^y$$

Equilibrio de Precipitación y Sales Poco Solubles: Solubilidad y Producto de Solubilidad (Kps)

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