What is the molarity of iodide ion in a solution prepared by mixing 20.0 mL of 0.100 M HI and 5.00 mL of 0.200 M KI?
A)0.180
B)8.33
C)0.120
D)1.50
E)0.0400

Question

Quizplus · Accepted Answer

First, calculate the moles of iodide ion (I-) present in the solution:
moles I- from HI = (0.100 M) x (0.0200 L) = 0.00200 mol I-
moles I- from KI = (0.200 M) x (0.00500 L) = 0.00100 mol I-
Total moles of I- = 0.00200 mol + 0.00100 mol = 0.00300 mol
Next, calculate the total volume of the solution:
20.0 mL + 5.00 mL = 25.0 mL = 0.0250 L
Finally, calculate the molarity of I-:
Molarity of I- = moles I- / volume of solution = 0.00300 mol / 0.0250 L = 0.120 M
Therefore, the answer is C) 0.120.

What Is the Molarity of Iodide Ion in a Solution