Solutions of the following:

Question

1. Find the number of 𝐾⁺ ions in 2.92 𝑔 of 𝐾₃𝑃𝑂1₄

2. Find the number of 𝑃𝑏²⁺ ions in 3.4 𝑚𝑜𝑙 of 𝑃𝑏𝑆𝑂₄

3. Convert the following 𝑝 − 𝑓𝑢𝑛𝑐𝑡𝑖𝑜𝑛𝑠 to molar concentrations:

a. 𝑝𝐻 = 1.020

b. 𝑝𝑂𝐻 = 5.72

c. 𝑝𝑀𝑛 = 0.567

d. 𝑝𝑁𝑂. = 4.5

e. 𝑝𝐵𝑎 = −0.231

f. 𝑝𝐶𝑙 = 0.098

4. Average human blood contains 300 𝑛𝑚𝑜𝑙𝑒𝑠 of hemoglobin(Hb) per liter of plasma and 2.2 𝑚𝑚𝑜𝑙/𝑙𝑖𝑡𝑒𝑟 of whole blood. Calculate

a. The molar concentration in each of this media

b. 𝑝𝐻𝑏 in the plasma on human serum.

5. Describe the preparation of 750 𝑚𝐿 𝑜𝑓 6.00 𝑀 𝐻₃𝑃𝑂₄ from the commercial reagent that is 86% 𝐻₃𝑃𝑂₄(𝑤/𝑤) and has a specific gravity of 1.71.

6. Calculate the p-value for each of the indicated ions in the following: 𝐶𝑢²⁺, 𝑍𝑛²⁺, and 𝑁𝑂_-3 in a solution that is 5.78 × 10^-2 𝑀 in 𝐶𝑢(𝑁𝑂₃)₂ and 0.204 𝑀 in 𝑍𝑛(𝑁𝑂₃)₂

7. A solution was prepared by dissolving 1210 𝑚𝑔 of 𝐾₃𝐹𝑒(𝐶𝑁)₆ (𝑀 = 329.2 𝑔/𝑚𝑜𝑙) in sufficient water to give 775 𝑚𝐿. Calculate the following:

a. The molar analytical concentration of 𝐾₃𝐹𝑒(𝐶𝑁)₆.

b. The molar concentration of 𝐾⁺.

c. The weight/volume percentage of 𝐾₃𝐹𝑒(𝐶𝑁)₆

d. the molar concentration of 𝐹𝑒(𝐶𝑁)₆^3-

e. 𝑝𝐹𝑒(𝐶𝑁)₆ for the solution.

8. A 12.5% (𝑤/𝑤) 𝑁𝑖𝐶𝑙₂ (129.61 𝑔/𝑚𝑜𝑙) solution has a density of 1.149 𝑔/𝑚𝐿. Calculate:

a. The molar concentration of 𝑁𝑖𝐶𝑙₂ in this solution

b. The molar 𝐶𝑙^- concentration of the solution

c. The mass in grams of 𝑁𝑖𝐶𝑙₂ contained in each liter of this solution.

9. Describe the preparation of the following solutions:

a. 5.00 𝐿 𝑜𝑓 0.0500 𝑀 𝐾𝑀𝑛𝑂₄ from the solid reagent.

b. 4.00 𝐿 𝑜𝑓 0.250 𝑀 𝐻𝐶𝑙𝑂₄, starting with an 8.00 𝑀 solution of the reagent.

c. 400 𝑚𝐿 of a solution that is 0.0250 𝑀 𝑖𝑛 𝐼₂, starting with 𝑀𝑔𝐼₂.

d. 1.50 𝐿 of a solution that is 12.0 𝑝𝑝𝑚 in 𝐾⁺, starting with solid 𝐾₄𝐹𝑒(𝐶𝑁)₆.

10. Find the number of millimoles of solute in:

a. 226 𝑚𝐿 of 0.320 𝑀 𝐻𝐶𝑙𝑂₄.

b. 25.0 𝐿 of 8.05 × 10^-3 𝑀 𝐾₂𝐶𝑟𝑂₄.

c. 6.00 𝐿 of an aqueous solution that contains 6.75 𝑝𝑝𝑚 𝑜𝑓 𝐴𝑔𝑁𝑂₃.

d. 537 𝑚𝐿 of 0.0200 𝑀 𝐾𝑂𝐻

e. 750 𝑚𝐿 of 3.25 × 10^-3 𝑀 𝐾𝑆𝐶𝑁

Answer 1

1. Find the number of 𝐾⁺ ions in 2.92 𝑔 of 𝐾₃𝑃𝑂₄

molar mass K3PO4 = 212 g / mol

2.92 g 𝐾₃𝑃𝑂₄ x 1 mol 𝐾₃𝑃𝑂₄ /212 g x 3 mol K⁺ / mol 𝐾₃𝑃𝑂₄ x 6.02x10²³ K⁺ ions / mol = 2.49x10²² K⁺ ions

3. Convert the following 𝑝 − 𝑓𝑢𝑛𝑐𝑡𝑖𝑜𝑛𝑠 to molar concentrations: NOTE: since p means negative log, simply take the anti log of the value to get the answer:

a. 𝑝𝐻 = 1.020; [H+] = 1x10^-1.020 = 9.55x10^-2 M

b. 𝑝𝑂𝐻 = 5.72; [OH-] = 1x10^-5.72 = 1.91x10^-6 M

c. 𝑝𝑀𝑛 = 0.567; [Mn] = 1x10-0^.567 = 2.71x10^-1 = 0.271 M

d. 𝑝𝑁𝑂. = 4.5

e. 𝑝𝐵𝑎 = −0.231

f. 𝑝𝐶𝑙 = 0.098