Question

What is the molarity of a solution composed of 5.85 g of potassium iodide, KI, dissolved

in enough water to make 0.125 L of solution?
los afuso

Answer 1

0.282 M

General Formulas and Concepts:

Chemistry - Solutions

• Reading a Periodic Table
• Using Dimensional Analysis
• Molarity = moles of solute / liters of solution

Step-by-step explanation:

Step 1: Define

5.85 g KI

0.125 L

Step 2: Identify Conversions

Molar Mass of K - 39.10 g/mol

Molar Mass of I - 126.90 g/mol

Molar Mass of KI - 39.10 + 126.90 = 166 g/mol

Step 3: Convert

`5.85 \ g \ KI((1 \ mol \ KI)/(166 \ g \ KI) )` = 0.035241 mol KI

Step 4: Find Molarity

M = 0.035241 mol KI / 0.125 L

M = 0.281928

Step 5: Check

We are given 3 sig figs. Follow sig fig rules and round.

0.281928 M ≈ 0.282 M