Question

question 4 (1 point) retake question
calculate the molarity of 12.4 g kcl in 289.2 ml solution
m kcl
question 5 (1 point) retake question
calculate the molarity of 16.4 g cacl₂ in 0.614 l solution
m cacl₂

Explanation:

Question 4

Step 1: Calculate moles of KCl

Molar mass of KCl: K (39.10 g/mol) + Cl (35.45 g/mol) = 74.55 g/mol.
Moles = $\frac{mass}{molar\ mass}$ = $\frac{12.4\ g}{74.55\ g/mol}$ ≈ 0.1663 mol.

Step 2: Convert volume to liters

289.2 mL = $\frac{289.2}{1000}$ L = 0.2892 L.

Step 3: Calculate molarity

Molarity (M) = $\frac{moles}{volume\ (L)}$ = $\frac{0.1663\ mol}{0.2892\ L}$ ≈ 0.575 M.

Question 5

Step 1: Calculate moles of CaCl₂

Molar mass of CaCl₂: Ca (40.08 g/mol) + 2×Cl (35.45 g/mol) = 110.98 g/mol.
Moles = $\frac{mass}{molar\ mass}$ = $\frac{16.4\ g}{110.98\ g/mol}$ ≈ 0.1477 mol.

Step 2: Calculate molarity

Molarity (M) = $\frac{moles}{volume\ (L)}$ = $\frac{0.1477\ mol}{0.614\ L}$ ≈ 0.241 M.

Answer:

s:
Question 4: $\boxed{0.575}$ M KCl
Question 5: $\boxed{0.241}$ M CaCl₂