How many moles are present in 168 g of KOH?

• A. 2.5 moles
• B. 4.2 moles
• C. 1.0 mole
• D. 3.0 moles

Answer: (D)

Verified step by step guidance

1. Identify the given information: the mass of KOH is 168 g, and you need to find the number of moles.
2. Calculate the molar mass of KOH by adding the atomic masses of potassium (K), oxygen (O), and hydrogen (H). Use the periodic table values: K ≈ 39.1 g/mol, O ≈ 16.0 g/mol, H ≈ 1.0 g/mol. So, molar mass of KOH = 39.1 + 16.0 + 1.0 g/mol.
3. Use the formula relating mass, moles, and molar mass: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\).
4. Substitute the given mass (168 g) and the calculated molar mass of KOH into the formula to find the number of moles.
5. Perform the division to find the number of moles of KOH present in 168 g.