Question

How many ml of a 0.155 M KCl solution contain 2.55 g KCl?

a. 221 mL of KCl solution
b. 165 mL of KCl solution
c. 330 mL of KCl solution
d. 110 mL of KCl solution

Answer 1

To find the volume of a 0.155 M KCl solution that contains 2.55 g KCl, calculate the moles of KCl and then divide by the molarity of the solution. The correct answer is approximately 221 mL of KCl solution.

Step-by-step explanation:

The question is asking to calculate the volume of a 0.155 M KCl solution that contains 2.55 g KCl. To answer this question, we perform the following steps:

1. Calculate the number of moles of KCl using the given mass (2.55 g) and the molar mass of KCl (74.55 g/mol).
2. Use the molarity of the solution (0.155 M), which is the moles of solute per liter of solution, to calculate the required volume of the solution.

Here's how:

1. Moles of KCl = Mass of KCl / Molar mass of KCl = 2.55 g / 74.55 g/mol = 0.0342 moles
2. Volume of solution = Moles of KCl / Molarity of solution = 0.0342 moles / 0.155 M = 0.2206 L, which is equivalent to 220.6 mL

Therefore, the correct answer is (a) 221 mL of KCl solution.