If you have 149 grams of potassium chloride (KCl), how many moles of KCl do you have?

• A. 4.00 moles
• B. 0.50 moles
• C. 2.00 moles
• D. 1.00 mole

Answer: (C)

Verified step by step guidance

1. Identify the given quantity and what is asked: You have 149 grams of potassium chloride (KCl) and need to find the number of moles.
2. Find the molar mass of KCl by adding the atomic masses of potassium (K) and chlorine (Cl). Use the periodic table values: approximately 39.10 g/mol for K and 35.45 g/mol for Cl.
3. Calculate the molar mass of KCl using the formula: \(\text{Molar mass of KCl} = 39.10 + 35.45\) g/mol.
4. Use the formula to convert grams to moles: \(\text{moles} = \frac{\text{mass in grams}}{\text{molar mass}}\).
5. Substitute the values into the formula: \(\text{moles of KCl} = \frac{149}{\text{molar mass of KCl}}\) and solve for moles.