Question

concentration of iodide ions?
0.25 mol/l calcium iodide or 0.45 mol/l
potassium iodide

○ potassium iodide

○ calcium iodide

○ they contain the same concentration of
iodide ions.

○ neither solution will contain iodide ions.

a solution of sodium hydroxide has a h+=
10^-12. the ph is which of the following?

○ 12

○ -12

○ 6

○ 7

a 11.15 mol/l acetic acid solution is an
example of what type of solution?

○ a concentrated weak acid

○ a dilute weak acid

○ a concentrated strong acid

○ a dilute strong acid

Explanation:

Step1: Calculate iodide in calcium iodide

Calcium iodide: $\text{CaI}_2
ightarrow \text{Ca}^{2+} + 2\text{I}^-$, so $[\text{I}^-] = 2 \times 0.25\ \text{mol/L} = 0.50\ \text{mol/L}$

Step2: Calculate iodide in potassium iodide

Potassium iodide: $\text{KI}
ightarrow \text{K}^+ + \text{I}^-$, so $[\text{I}^-] = 1 \times 0.45\ \text{mol/L} = 0.45\ \text{mol/L}$

Step3: Compare iodide concentrations

$0.50\ \text{mol/L} > 0.45\ \text{mol/L}$, so calcium iodide has higher $[\text{I}^-]$

Step4: Calculate pH from $[\text{H}^+]$

$\text{pH} = -\log_{10}[\text{H}^+] = -\log_{10}(10^{-12}) = 12$

Step5: Classify acetic acid solution

Acetic acid is a weak acid (does not fully dissociate); 11.15 mol/L is a high concentration, so it is a concentrated weak acid.

Answer:

1. calcium iodide
2. 12
3. a concentrated weak acid